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SDE II / L5
Own a feature or service through design, implementation, release and operation. Explain tradeoffs, incident handling and collaboration beyond the immediate coding task.
What changes at this level
Show independent feature or service delivery: API and data-model choices, failure behavior, tests, release and operation, plus how you resolved ambiguity without losing implementation quality.
Level names are a preparation mapping. The active requisition and recruiter-confirmed scope are authoritative. Open the role’s official guidance.
Get an interview for SDE II
Start with a current requisition. Its qualifications, location, working arrangement and domain requirements determine fit; a single posting is not a global eligibility rule.
Role scope: Own a feature or service through design, implementation, release and operation. Explain tradeoffs, incident handling and collaboration beyond the immediate coding task.
Choose the entry route that fits your situation
Direct application
Best for: Candidates who have found a current requisition that matches their role, location, work authorization and relevant skills.
Search Amazon Jobs by role, location, business and relevant skills. Record the job ID, then read both basic and preferred qualifications before tailoring the resume and completing the application. A direct application is a complete route; a referral is not required.
Best for: Candidates who know an employee familiar enough with their work to make a specific, truthful introduction to a matching requisition.
A referral starts an introduction. Amazon contacts the referred candidate to complete the application, and further contact depends on selection. Send the employee the job ID, a relevant resume and two or three sentences of evidence; do not ask them to overstate the relationship or imply that referral bypasses review.
Best for: Candidates with a close role match, a recruiter who covers the relevant organization or a concise question about an active process.
Introduce the role by title and job ID, state the most relevant evidence of fit, and ask one answerable question. A short, relevant note is useful; repeated generic messages or requests for a guaranteed interview are not.
Choose a current requisition and save its exact title, location and job ID.
Read the basic and preferred qualifications, working arrangement and role-specific domain expectations.
Tailor the resume to truthful, relevant work and make your own decisions and contributions easy to identify.
Prepare a two- or three-sentence evidence-of-fit note for a referral or recruiter conversation.
Complete the required application yourself, then track its status in the Amazon Jobs profile and keep recruiter contact details.
Confirm personal questions about location, sponsorship, work authorization or accommodations with recruiting or the linked official policy; this guide does not provide immigration or employment advice.
Demonstrate service ownership from decision through operation.
Include
Features or services you independently delivered, including the design choice and your implementation contribution
Release, observability, incident or reliability work that shows you owned behavior after launch
A concrete ambiguity, tradeoff or collaboration problem and the outcome you can substantiate
Avoid
Stopping each bullet at implementation with no release or operating context
Attributing team-wide architecture to yourself
Inflated scale or percentages whose baseline you cannot explain
Outreach drafts
Copy and adapt these original drafts yourself. They do not send a message or imply a response.
Referral request
Use when: You know the employee well enough for them to assess your fit.
Hi [name] - I’m applying to [role, job ID] in [location]. My most relevant evidence is [one specific project or responsibility] and [one relevant skill/outcome]. If you’re comfortable referring me based on what you know of my work, I can send the tailored resume and requisition link. No pressure if the fit or timing is not right.
Recruiter introduction
Use when: You have identified an active role and a recruiter connected to the relevant hiring area.
Hello [name] - I’m interested in [role, job ID] in [location]. I’ve [specific relevant ownership or technical result], and the role’s emphasis on [qualification/domain] matches my experience with [brief evidence]. Is this requisition in your area, and is there anything role-specific I should clarify before applying?
Polite status follow-up
Use when: A stated update window has passed or you have a real scheduling constraint.
Hi [name] - I’m following up on [role, job ID] after [assessment/interview] on [date]. I remain interested and wanted to check whether there is an updated timeline or any action needed from me. I also have [brief, factual deadline if applicable] and would appreciate any guidance you can share. Thank you.
Application questions
What does a referral change?
It creates an employee introduction tied to a role; it does not complete the application, guarantee recruiter contact or bypass evaluation. Amazon says the referred candidate is contacted to complete the application, and further contact depends on selection.
Amazon’s corporate application FAQ, checked September 14, 2026, permits up to ten simultaneous applications or interview processes and notes that separate recruiters may be involved. That is a ceiling, not a target: apply to a small set of roles you can credibly match and track each job ID.
Where do requirements for location, working arrangement and sponsorship come from?
Use the active requisition and Amazon’s application FAQ, then ask recruiting about your case. Requirements vary by role and location; do not convert one posting’s qualifications or work arrangement into a global rule.
Amazon’s published format has two coding questions in 90 minutes, system-design scenarios and work styles. AI-assisted technical assessments are also in use; check which format your invitation describes before preparing.
Four 55-minute interviews
This is Amazon’s published SDE II loop. It includes coding and at least one system-design question. A separate technical screen can depend on the role.
Debrief and decision
After the loop, interviewers submit feedback for debrief and recruiting communicates the outcome or another evaluation step. Amazon’s FAQ states goals of an update within two business days after a phone interview and five after a loop; these are goals, not guarantees. If the role closes, ask whether a similar role is being considered and whether more interviews are needed - no automatic transfer is promised.
Leadership Principles throughout: Expect behavioral questions alongside technical work. Prepare to explain your decisions, your personal contribution and the results.
Recent guide change: Amazon’s January 2026 confirmation of explicitly AI-assisted technical assessments now has dedicated preparation guidance here. This does not mean every role, country or assessment uses that format; identify the format from your invitation.
Which assessment did you receive?
Amazon's dedicated SDE II page describes Coding, System Design and Work Styles, plus an optional survey. Newer candidates also report an AI-assisted coding variant. These are different assessment descriptions: do not combine them into extra required rounds. Your invitation controls the sections, question counts and timers.
Choose your preparation plan
A practical schedule for SDE II. Choose the time you have, then use your mock interviews to decide what needs more work.
These plans are Engineering Foundry recommendations. Match the exercises to your confirmed interview format.
7-day triage
Day 1: Confirm the format and find gaps
Confirm the OA’s technical format and the allocation of coding and design interviews. Try one coding problem, sketch a service and tell an ownership story. Keep an error log and choose projects covering delivery and production operation.
Rotate graph or tree, heap or interval, and window or dynamic-programming exercises with follow-ups. Rehearse the OA in your invitation: the published version has two coding problems in 90 minutes; an AI-assisted version needs repository practice too. Review failed cases and test every suggested code change.
Implement order checkout with inventory and payment interfaces; test a retried request and a payment failure. Then outline a notification service's API, data model and delivery flow. Explain a bottleneck, duplicate delivery and recovery.
Day 4: Defend ownership and results
Rehearse delivery under constraints, an incident, disagreement and a quality improvement. Map real examples to the Leadership Principles and check the measurements. Combine one story with coding and answer why you chose that approach.
Day 5: Trace a service into production
Review a service you helped deliver: requirements, code, rollout, monitoring and an operational problem. Ask a peer to challenge one tradeoff, a retry path and your personal contribution. Compare this with a second project if time permits.
Day 6: Run a mixed mock and fix the gap
Rehearse a confirmed session using its actual time limit, with behavioral questions alongside coding or design. Review your biggest weakness, then use a different problem to test the correction. Check the coding and meeting environment.
Practice these five representative coding exercises, then use the full Amazon-tagged DSA collection to keep going. Company tags and candidate reports are preparation signals, not predictions of your interview questions.
Coding 2,021
Amazon-tagged questions in the current public company catalog
Course ordering / topological sort
Named problem in a candidate account. Course Schedule II is named in two reviewed accounts.
Reported at: SDE I / L4, SDE II / L5. Recommended for practice: SDE I / L4, SDE II / L5, SDE III / L6.
Exercise-specific practice: Model prerequisites, track indegree or traversal state, detect cycles and explain why the output is valid.
Level extension for SDE II / L5: Make the implementation robust under a changed requirement; test failure behavior and connect the data-structure choice to a service or API consequence.
Named problem and a reported variant. Rotting Oranges is named in one report and a variant is described in another.
Coding / DSA
Show how you reach a correct solution and adapt it when requirements change.
Clarify. Restate inputs, outputs and constraints. Work through one example before coding.
Explain. Start with a correct approach, state its complexity, then justify any improvement.
Implement and test. Write complete code. Check a normal case, empty input, duplicates and a case that could break your approach.
Handle the follow-up. Explain which assumption changed before modifying your solution.
Cover the fundamentals: arrays and strings, hash maps, trees and graphs, heaps, binary search, and dynamic programming. Practice explaining your choices, not recognizing a remembered answer.
Try one coding rehearsal
Implement a cache or solve an unfamiliar graph problem, then change a requirement: add expiration, accept duplicate inputs or reduce memory. Explain which assumption changed, update your code and test it.
Practice tasks and readiness checks in this guide are Engineering Foundry recommendations, not Amazon scoring rules or reported interview questions.
System Design
Amazon includes system design at SDE II. Prepare both a small object-oriented model and an end-to-end service design; ask whether they are separate interviews and whether runnable code is expected.
Make a small design work
Agree on the use cases and whether runnable code is required.
Define responsibilities, interfaces and valid state changes. Walk one request through them.
Implement the critical operation; handle invalid input, retries and one new requirement.
Try it: Design order checkout with inventory, order and payment interfaces. Implement the checkout workflow, prevent a retried request from charging twice, and test stock shortages and payment failures. Explain which component owns each state change.
Design an end-to-end service
Start with requirements, an API and a data model. Follow a write and a read through the system, then explain the bottleneck, a failure case and a tradeoff.
Try it: Design a notification service. Add duplicate delivery and a failed provider; explain retries, deduplication and what users see.
Behavioral & Leadership Principles
Prepare for these questions throughout the loop, including coding and design interviews. Use specific events and expect follow-ups about your decisions.
Prepare examples of a release under constraints, a production defect, an ambiguous requirement, a disagreement and a quality improvement. Explain the decisions you owned and how you measured the outcome.
Build a story you can defend
Situation and stakes: name the specific event, customer or engineering consequence and the constraint that made it difficult.
Individual responsibility: state what you owned, what the team owned and what decision was yours to make.
Decision and alternatives: explain the options, evidence, uncertainty and why you chose this path.
Action: describe the technical and interpersonal work you personally performed, including how you handled disagreement or new information.
Credible outcome: give a measured result when you know the baseline, or a concrete observable outcome when a number would be fabricated.
Reflection: say what you learned, what you would change and how that learning affected later work.
A genuine experience can demonstrate several principles because real work has multiple dimensions. Change the emphasis to answer the prompt, but keep alternate examples ready and do not force one rehearsed story into every principle.
Annotated scope example: SDE II / L5
A retried checkout request could create duplicate work. The candidate compared idempotency options, added a request key and recovery test, monitored duplicates after rollout and documented the client contract. The story connects implementation to service ownership.
Rehearse: Tell the story in about two minutes, then answer “Why that approach?”, “What did you do yourself?” and “How do you know it worked?” Don’t invent numbers to make a story sound stronger.
A Bar Raiser is an interviewer role. It does not guarantee an extra interview or a behavioral-only session.
Interview day and next steps
Confirm the real logistics in your invitation, then use the published follow-up goals as prompts - not guarantees.
Readiness checks for SDE II
I completed a mock matching my OA invitation: the published two-problem 90-minute coding version, or coding and repository work when AI assistance is explicitly specified.If not: Use the matching OA rehearsal
I rehearsed delivery, incident and disagreement stories with specific evidence and repeated why/what-did-you-own follow-ups.If not: Rebuild the missing story
Before interview day
Confirm the date, time zone, session order, expected breaks and the recruiter or coordinator to contact.
Open the recruiter-selected meeting link and follow its installation or browser instructions; Amazon currently documents Zoom or Chime, but the invitation controls.
Confirm the coding, drawing or repository environment, supported language, permitted assistance and whether any supplied tutorial or mock should be completed.
Ask which spoken language each interview will use; Amazon says language can vary with the role.
Request an accommodation through the country-specific route early, or contact recruiting when the country is not listed.
Published traditional SDE II assessment
Evidence scope: Amazon’s official SDE II guidance; requisition and invitation details can still vary.
Work involved: Two coding questions, scenario-based system-design judgment, work styles and an optional feedback survey. The scenario section is not a live architecture whiteboard interview.
Timing: The dedicated OA page gives a 90-minute coding limit and estimates about 15 minutes for system design and 10 for work styles; the SDE II overview gives 20 and 8 minutes. Preserve the source-specific estimates and follow the invitation rather than adding them into one fictional timer.
Practice: Run a two-problem 90-minute coding mock and separately rehearse scenario decisions using customer impact, maintainability, urgency and missing information.
Confirm before starting: Section names, which sections are timed, current estimates or limits, platform tutorial, supported language and permitted resources.
Explicitly AI-assisted technical assessment
Evidence scope: Amazon officially confirms this assessment type exists. August and September 2026 reports from the same author illustrate a DSA-plus-repository variant; they are not independent corroboration or a universal SDE II format.
Work involved: The reports describe one DSA task and one AI-assisted repository task, followed by noncoding assessment work.
Timing: The August account reports 40 minutes for DSA and 60 for repository work. These are one author’s reported timers, not official limits for every SDE II candidate.
Practice: Use an unfamiliar repository to diagnose one defect, inspect the assistant’s suggestion, make a scoped change, test failure and edge paths and explain the result yourself.
Confirm before starting: Task timers, repository framework, expected deliverable, tests, supplied assistant and exactly where its use is permitted.
Invitation is unclear
Evidence scope: Any candidate whose section names or instructions do not clearly match either description.
Work involved: Do not assume the published system-design scenarios, a reported work simulation and a live system-design session are interchangeable or cumulative.
Timing: Keep unknown limits unknown and use only the timing printed in the invitation or platform.
Practice: Maintain coding, repository-reading and scenario-judgment readiness while completing the authorized tutorial.
Confirm before starting: Ask recruiting for each section’s name, purpose, timer, technical deliverable, authorized mock and AI/tool permissions before starting.
Check which technical format you received
Published coding format: 2 problems in 90 minutes: The dedicated OA guide specifies two coding questions in a timed 90-minute section. Prepare data structures, algorithms and readable, robust implementation. Its noncoding sections have estimated completion times rather than the same countdown.
Reported AI format: 1 DSA task + 1 repository task: Amazon confirms assessments with an interactive AI assistant. An August 2026 SDE candidate reports 100 minutes: 40 for DSA and 60 for a repository task. A September SDE II account from the same author also describes one DSA problem and AI-assisted repository debugging. These reports do not establish a universal SDE II timer.
The other OA sections
System Design in the published OA: Untimed, approximately 15 minutes on the dedicated OA page. Rate actions in fictional engineering scenarios involving prioritization, maintainability, ambiguity and tradeoffs. This section does not require a whiteboard or architecture diagram. The number of scenarios is not published.
Work Simulation in the reported AI variant: The August report lists about 45 minutes of software-development decisions. Do not assume this is an additional section alongside the published System Design section. Its question count is unconfirmed; follow the names and order in your invitation.
Work Styles: The dedicated OA page estimates 10 minutes, untimed, covering software-engineering preferences and general work style. It uses multiple-choice questions related to Leadership Principles. Total question count is not published; timings in newer candidate reports differ.
Optional feedback survey: The dedicated SDE II OA page lists about 1 minute. It is feedback on the experience; the question count is not published. Complete every required assessment section and check for submission confirmation.
Coding difficulty: Amazon does not publish an Easy/Medium/Hard mix or a pass threshold. Rehearse unfamiliar Medium problems plus harder follow-ups, and review correctness and complexity. The August candidate described DSA as Medium to Hard; repository work tests practical debugging in an existing application.
How to prepare for the OA
Use a two-problem, 90-minute mock for the published format. If your invitation names the AI variant, match its separate task timers instead.
If your invitation includes the AI task, open an unfamiliar practice repository, run its tests and trace one failure. Ask the permitted assistant a focused question, review its proposed change, then rerun tests and check an edge case. Be able to explain the fix yourself.
For scenarios, identify customer impact, urgency and missing information before rating actions. Read each section's instructions; use only the tools permitted there.
Keep these AI topics separate
An explicitly provided or permitted assistant in a technical assessment is limited to that section and its instructions.
A reported GenAI-fluency interview or discussion can cover a real workflow, verification, limitations and engineering judgment; reports do not establish one fixed or universal round.
Amazon’s use of AI in its own hiring systems, including transcription or role matching, is separate from candidate permission to use AI during an assessment.
Practice an AI-assisted repository task
Engineering Foundry preparation for an explicitly AI-assisted repository task; not a claim about a universal Amazon assessment, repository, framework or assistant.
Read the task, repository notes and permitted-tool instructions before prompting or editing.
Identify the entry point, relevant modules, tests and expected behavior. Trace the smallest path that could explain the failure.
Run baseline checks where the environment permits. Record an existing failure separately from any regression you introduce.
Form a hypothesis, then give the permitted assistant focused context and a bounded request instead of asking it to rewrite the project.
Inspect every suggestion against the code and requirements. Reject invented APIs, unsupported assumptions and unrelated cleanup.
Make a small, understandable fix or feature change and keep the diff scoped to the task.
Test normal behavior, boundary cases and a relevant failure path; rerun the baseline and inspect the final diff.
Explain the change, tradeoffs, limitations and verification in your own words.
Common mistakes
Accepting a plausible patch without reading the changed code
Testing only the visible happy path
Changing unrelated modules or expanding the task
Spending the session configuring optional tools instead of understanding the repository
Assuming AI permission in one section applies to coding, work-style or interview sections elsewhere
Recovery when the assistant is wrong: When the assistant gives poor advice, narrow the problem, restate one observed failure and the relevant code, verify the hypothesis manually and keep control of the final solution. A smaller correct change you can defend is stronger than a broad patch you cannot explain.
Repair an API validation gap
Engineering Foundry reading exercise; it is not an Amazon question and is not runnable from this guide.
Diagnosis: A profile update handler validates displayName only when the value is truthy. An empty string therefore skips validation and reaches storage. Reproduce the behavior, read the request schema and confirm whether omission and an empty value have different meanings.
Inadequate fix: Checking only that displayName is a string still accepts whitespace and may accidentally make an optional field required. It treats the symptom without preserving the endpoint contract.
Better change: When the field is present, normalize it according to the existing contract and reject an empty result. Leave omission behavior unchanged, use the project’s established error shape and avoid refactoring unrelated handlers.
Tests that distinguish the fix
A valid display name updates successfully.
An empty or whitespace-only value returns the established validation error.
An omitted optional field preserves the previous value.
An unrelated valid field still updates, guarding against an overbroad rejection.
The pre-existing baseline suite still has the same result after the focused change.
Interview rounds: question counts, topics and difficulty
Amazon publishes four 55-minute loop interviews. The allocation below can vary: coding, design and Leadership Principles often share a session. Reported counts are examples; difficulty targets are Foundry recommendations.
Recruiter and role alignment
How many: No standard question count; Amazon describes recruiter contact after a successful assessment.
What comes up: Explain the services and features you have owned. Confirm team scope, scheduling, coding environment and how low-level and system design are allocated.
How many: Reviewed accounts include 1–2 main coding problems per session, plus follow-ups.
What comes up: One candidate reports a Medium DFS problem with 1–2 theoretical follow-ups and another custom-data-structure task. A Dublin account describes two problems involving a heap and a linked list.
Coding difficulty: Foundry target: Medium core with selected Hard stretch problems; no official distribution.
Engineering Foundry evaluation guidance - not Amazon’s internal rubric
Strong signals
Explains the invariant and complexity, implements complete code and tests a case likely to break the approach.
Independent delivery through API/data choices, failure handling, tests, release and operation.
Weak signals
Recognizes a pattern but cannot justify correctness, finish the implementation or adapt a changed requirement.
A plausible design or implementation with no ownership of ambiguity, retries, production behavior or measurement.
Likely follow-up depth
What assumption does this optimization rely on, and what changes if input, memory or query requirements change?
What requirement was ambiguous, which tradeoff did you own and how did the service behave after launch?
Next practice action: Solve one unfamiliar problem, test it, then change one constraint and implement the adaptation.
How many: Individual accounts describe one main design exercise with extensions.
What comes up: Examples include product classes and order totals, or file filtering by size and extension. Define responsibilities and APIs, implement the critical operation, and show how a new requirement fits.
Practice depth: Foundry target: production-minded code and tests; LeetCode difficulty does not apply.
Engineering Foundry evaluation guidance - not Amazon’s internal rubric
Strong signals
Defines responsibilities, interfaces, valid state changes, errors and a critical operation that can be tested.
Independent delivery through API/data choices, failure handling, tests, release and operation.
Weak signals
Names patterns or draws classes without showing behavior, invalid transitions, concurrency or extension.
A plausible design or implementation with no ownership of ambiguity, retries, production behavior or measurement.
Likely follow-up depth
Who owns this state, what happens on a retry or concurrent call and how would a new requirement fit?
What requirement was ambiguous, which tradeoff did you own and how did the service behave after launch?
Next practice action: Model one bounded workflow, implement its critical operation and test success, rejection and retry behavior.
How many: Official: at least one software-systems-design question in the loop.
What comes up: A reported e-commerce design covered requirements, architecture, APIs, database tradeoffs, scaling and observability. Interviewers probe and extend the design.
Practice depth: Foundry target: one end-to-end service per rehearsal, with a bottleneck and a failure case; the rehearsal count is editorial.
Engineering Foundry evaluation guidance - not Amazon’s internal rubric
Strong signals
Starts from requirements, traces data through the system and defends a bottleneck, failure mode and tradeoff.
Independent delivery through API/data choices, failure handling, tests, release and operation.
Weak signals
Draws familiar components without workload assumptions, data ownership, recovery or an operating plan.
A plausible design or implementation with no ownership of ambiguity, retries, production behavior or measurement.
Likely follow-up depth
What breaks first, how does the system recover and which evidence would make you choose the strongest alternative?
What requirement was ambiguous, which tradeoff did you own and how did the service behave after launch?
Next practice action: Defend one service design, then introduce a failure and a changed scale constraint and revise only what is necessary.
How many: No fixed count or guaranteed separate project round.
What comes up: A Bengaluru candidate reports current-project architecture alongside coding. Prepare one service you owned: decisions, data flow, release risks, incidents, measurements and your personal contribution.
Engineering Foundry evaluation guidance - not Amazon’s internal rubric
Strong signals
Separates personal decisions from team execution and connects architecture, delivery, operations and credible outcomes.
Independent delivery through API/data choices, failure handling, tests, release and operation.
Weak signals
Claims success or influence without alternatives, implementation evidence, a baseline or lessons from failure.
A plausible design or implementation with no ownership of ambiguity, retries, production behavior or measurement.
Likely follow-up depth
What did you decide, what was the strongest rejected option, how do you know it worked and what would you change now?
What requirement was ambiguous, which tradeoff did you own and how did the service behave after launch?
Next practice action: Ask a peer to challenge one real project from problem framing through implementation, operation and outcome.
How many: Official: each interviewer typically asks 2–3 behavioral questions.
What comes up: Use concrete successes, challenges and decisions, with follow-ups about what you did and why. A Bar Raiser conversation can mix technical and behavioral topics; do not count it as an automatic extra round.
How many: No fixed AI-question count or separate SDE II AI round established.
What comes up: Amazon’s broad topic list includes ML and AI. Foundry rehearsal: explain a real use of generated code, how you verify correctness, which data you protect and when you would avoid AI.
Engineering Foundry evaluation guidance - not Amazon’s internal rubric
Strong signals
Uses a real workflow, verifies generated output, names limitations and keeps engineering judgment and data boundaries explicit.
Independent delivery through API/data choices, failure handling, tests, release and operation.
Weak signals
Treats AI output as authoritative, gives only tool enthusiasm or assumes permission and suitability without checking.
A plausible design or implementation with no ownership of ambiguity, retries, production behavior or measurement.
Likely follow-up depth
How did you detect a wrong output, when would manual work be safer and what information should not be shared?
What requirement was ambiguous, which tradeoff did you own and how did the service behave after launch?
Next practice action: Review one plausible but flawed generated change, create a counterexample, correct it and explain the verification.
The dedicated OA page gives a 90-minute coding limit and estimates about 15 minutes for system design and 10 for work styles; the SDE II overview gives 20 and 8 minutes. Preserve the source-specific estimates and follow the invitation rather than adding them into one fictional timer.
A recent candidate account reported four half-technical, half-behavioral sessions covering DSA, LLD, ambiguous problem solving and system design; five-session variants remain candidate-reported.
Candidate reports describe individual experiences. They do not establish a fixed coding-round count or predict your questions.
Day 7: Review and get ready
Close each remaining error-log item with a tested solution, defended design, revised story or clarified recruiting requirement. Confirm the time zone, breaks, meeting link, language, tools, permitted assistance, accessibility needs and technical-problem contact. Prepare questions about the team, then leave time for rest instead of starting a large new topic.
Confirm the OA’s technical format and the allocation of coding and design interviews. Try one coding problem, sketch a service and tell an ownership story. Keep an error log and choose projects covering delivery and production operation.
Rotate graph or tree, heap or interval, and window or dynamic-programming exercises with follow-ups. Rehearse the OA in your invitation: the published version has two coding problems in 90 minutes; an AI-assisted version needs repository practice too. Review failed cases and test every suggested code change.
Implement order checkout with inventory and payment interfaces; test a retried request and a payment failure. Then outline a notification service's API, data model and delivery flow. Explain a bottleneck, duplicate delivery and recovery.
Days 8–9: Defend ownership and results
Rehearse delivery under constraints, an incident, disagreement and a quality improvement. Map real examples to the Leadership Principles and check the measurements. Combine one story with coding and answer why you chose that approach.
Days 10–11: Trace a service into production
Review a service you helped deliver: requirements, code, rollout, monitoring and an operational problem. Ask a peer to challenge one tradeoff, a retry path and your personal contribution. Compare this with a second project if time permits.
Days 12–13: Run a mixed mock and fix the gap
Rehearse a confirmed session using its actual time limit, with behavioral questions alongside coding or design. Review your biggest weakness, then use a different problem to test the correction. Check the coding and meeting environment.
Close each remaining error-log item with a tested solution, defended design, revised story or clarified recruiting requirement. Confirm the time zone, breaks, meeting link, language, tools, permitted assistance, accessibility needs and technical-problem contact. Prepare questions about the team, then leave time for rest instead of starting a large new topic.
Confirm the interview plan and diagnose coding, design and behavioral readiness. Rotate core coding patterns and record mistakes. Outline stories about delivery, incidents and conflict, and document two projects through release and operation.
Time coding exercises and implement follow-up changes. Rehearse the OA if it is still ahead. Practice both order-checkout object design and notification-service architecture; explain interfaces, persistence, retries, consistency and monitoring.
Days 15–21: Test judgment in mixed interviews
Alternate mixed mocks with repairs from your error log. Trace designs through failure and recovery. Rehearse Leadership Principle examples with skeptical follow-ups about decisions, production outcomes and what you personally owned.
Days 22–28: Run a mixed mock and fix the gap
Rehearse a confirmed session using its actual time limit, with behavioral questions alongside coding or design. Review your biggest weakness, then use a different problem to test the correction. Check the coding and meeting environment. Repeat only the sessions that expose a persistent gap; prepare questions about the team's work and expectations.
Close each remaining error-log item with a tested solution, defended design, revised story or clarified recruiting requirement. Confirm the time zone, breaks, meeting link, language, tools, permitted assistance, accessibility needs and technical-problem contact. Prepare questions about the team, then leave time for rest instead of starting a large new topic.
Reported at: SDE I / L4. Recommended for practice: SDE I / L4, SDE II / L5, SDE III / L6.
Exercise-specific practice: Initialize all sources together; count time by layers and handle unreachable cells and an already-complete grid.
Level extension for SDE II / L5: Make the implementation robust under a changed requirement; test failure behavior and connect the data-structure choice to a service or API consequence.
Related problems; exact match not established. One account names Domino and Tromino Tiling; another describes floor tiling. These are related, not necessarily identical problems.
Reported at: SDE I / L4, SDE II / L5. Recommended for practice: SDE I / L4, SDE II / L5, SDE III / L6.
Exercise-specific practice: Define a state before deriving transitions. Explain boundary values and why each arrangement is counted once.
Level extension for SDE II / L5: Make the implementation robust under a changed requirement; test failure behavior and connect the data-structure choice to a service or API consequence.
Named problem in a candidate account. Named in the reported 2026 SDE I loop.
Reported at: SDE I / L4. Recommended for practice: SDE I / L4, SDE II / L5, SDE III / L6.
Exercise-specific practice: Explain the pivot, successor and suffix transformation, including descending input and duplicate values.
Level extension for SDE II / L5: Make the implementation robust under a changed requirement; test failure behavior and connect the data-structure choice to a service or API consequence.
Candidate-reported variant. A celebrity-problem variant is reported.
Reported at: SDE I / L4. Recommended for practice: SDE I / L4, SDE II / L5, SDE III / L6.
Exercise-specific practice: Separate candidate elimination from final verification; explain the information needed to rule a candidate out.
Level extension for SDE II / L5: Make the implementation robust under a changed requirement; test failure behavior and connect the data-structure choice to a service or API consequence.
Amazon’s software-development topic list is broad; it does not mean every role tests every topic. Use the active requisition and recruiter-confirmed plan to decide which domain additions deserve time.
Databases
Look for: Storage engines, data modeling, consistency, query behavior, indexing or data-platform ownership in the requisition.
Practice: Explain one schema and access pattern, a consistency or indexing tradeoff and how failure or migration changes the choice.
Operating systems and concurrency
Look for: Runtime, kernel, performance, concurrency, scheduling, storage or low-level systems responsibilities.
Practice: Defend synchronization, memory/process boundaries, contention and a failure or performance measurement relevant to the role.
Practice: Explain resource constraints, update/rollback, intermittent connectivity and how hardware-software boundaries are tested.
Front-end engineering
Look for: Browser or application UI, accessibility, state management, performance, design systems or client-platform responsibilities.
Practice: Defend component/state boundaries, loading and failure states, accessibility and a measured performance or compatibility tradeoff.
ML and AI
Look for: Model development, evaluation, data pipelines, inference, ranking, responsible AI or AI-product integration.
Practice: Separate model quality from system behavior; explain evaluation data, latency/cost, failure handling, monitoring and when a non-AI solution is better.
Every principle is directly discoverable below. These are original practice questions and evaluation cues, not a list of questions Amazon promises to ask. Read Amazon’s official principles.
Customer Obsession
Connect a technical decision to a real user need and verify whether it helped.
Practice questions for SDE II
Describe a time user feedback changed your proposed solution.
When did you challenge an internal request because it would create a worse customer experience?
Describe a service improvement you prioritized because of customer pain despite competing feature work.
Follow-ups: How did you establish that this was the real problem? Which customer group benefited, and who might have been disadvantaged? What evidence showed improvement after release?
Strong answer signals
Direct evidence of user needs
An explicit tradeoff and a measured or observable outcome
Weak answer signals
Calling every stakeholder request a customer need
Only measuring work completed
Ownership
Take responsibility for an outcome and its consequences, including gaps between teams.
Practice questions for SDE II
Tell me about a problem you took responsibility for before someone assigned it to you.
Describe a commitment that went off track. What did you do after recognizing the risk?
Tell me about a production issue outside your immediate component that you helped resolve end to end.
Follow-ups: Which actions were yours rather than the team’s? What did you stop or renegotiate to take this on? Who owned the outcome after the immediate fix?
Strong answer signals
Clear accountability without exaggerated authority
A durable fix or explicit handoff
Weak answer signals
Heroic overtime as the entire solution
Blaming another team for an unresolved gap
Invent and Simplify
Reduce unnecessary complexity while preserving the behavior customers need.
Practice questions for SDE II
Describe a solution you made substantially simpler.
Tell me about an idea from outside your team that you adapted to solve a problem.
Tell me about a service or API you simplified. How did you show that important cases still worked?
Follow-ups: What complexity remained necessary? What alternatives did you discard? How did you measure adoption or reduced effort?
Strong answer signals
A specific before-and-after comparison
Attention to compatibility and adoption
Weak answer signals
Equating novelty with usefulness
Moving complexity to another team and calling it removed
Are Right, A Lot
Make defensible decisions and actively seek evidence that could prove you wrong.
Practice questions for SDE II
Tell me about an important judgment you made with incomplete information.
Describe a time new evidence caused you to reverse your position.
Tell me about choosing between two technical options with uncertain cost or performance.
Follow-ups: What did you know, assume and not know? Who disagreed, and how did their view affect your decision? What evidence would have changed your mind earlier?
Strong answer signals
Explicit uncertainty and disconfirming evidence
Judgment evaluated against information available at the time
Weak answer signals
Claiming to be right because the outcome happened to be good
Hiding a change of mind
Learn and Be Curious
Learn purposefully and convert new understanding into better engineering decisions.
Practice questions for SDE II
Tell me about something important you had to learn quickly.
Describe a belief about engineering that changed after deeper investigation.
Tell me about investigating a system outside your expertise and applying the learning to a service you owned.
Follow-ups: How did you choose credible learning sources? What did you build, test or explain to demonstrate understanding? What remained uncertain after you learned the basics?
Strong answer signals
Learning connected to a concrete result
Accurate limits on expertise
Weak answer signals
A list of courses with no application
Claiming mastery after superficial exposure
Hire and Develop the Best
Improve other people’s capability through specific feedback, support and opportunities.
Practice questions for SDE II
Tell me about helping someone become more effective.
Describe difficult feedback you gave and how you followed through.
Tell me about onboarding or mentoring an engineer. What changed in their independence or quality of work?
Follow-ups: How did you identify what the person needed? What did they do independently afterward? How did you know your approach was helping rather than creating dependence?
Strong answer signals
Specific feedback and follow-through
Credit for the other person’s own effort
Weak answer signals
Inventing hiring authority at entry level
Measuring mentorship only by meetings held
Insist on the Highest Standards
Set a defensible quality bar and fix mechanisms that allow defects to recur.
Practice questions for SDE II
Describe a time you raised the quality of a deliverable under pressure.
Tell me about a defect that changed how your team prevented problems.
Tell me about a recurring production defect you addressed through a lasting engineering change.
Follow-ups: What was the risk of accepting the existing quality? Why was your chosen standard appropriate rather than arbitrary? What evidence showed that recurrence decreased?
Strong answer signals
Risk-based quality decisions
Prevention and verification after the fix
Weak answer signals
Perfectionism without customer value
Treating every defect as an individual failure
Think Big
Find a larger valuable opportunity and make the path toward it credible.
Practice questions for SDE II
Tell me about a proposal that expanded what your team thought was possible.
Describe a small experiment that tested a much larger idea.
Tell me about extending a feature-level improvement into a reusable service or capability.
Follow-ups: Why was the larger opportunity worth pursuing? What was the smallest useful validation? What would have caused you to stop or narrow the idea?
Strong answer signals
Ambition connected to customer value
A realistic first step and decision points
Weak answer signals
Scale claims without a use case
A vision with no evidence or execution path
Bias for Action
Act at an appropriate speed while managing uncertainty and reversible versus irreversible choices.
Practice questions for SDE II
Tell me about a time waiting for complete information would have been costly.
Describe a quick decision you later adjusted.
Tell me about mitigating an incident or delivering a time-sensitive change with incomplete information.
Follow-ups: What made delay costly? What was the downside, and how did you contain it? What signal told you to continue, change course or roll back?
Strong answer signals
Explicit risk and rollback thinking
A concrete reason for the chosen speed
Weak answer signals
Speed used to excuse skipped essentials
Confusing activity with progress
Frugality
Use limited resources thoughtfully and account for the total cost of a decision.
Practice questions for SDE II
Describe achieving an important result with a tight resource constraint.
Tell me about reducing cost without simply shifting it elsewhere.
Tell me about improving a service’s cost while protecting its performance and reliability.
Follow-ups: What were the full operating and maintenance costs? What quality or capability did you preserve? Would your choice still be economical at a different scale?
Strong answer signals
Total-cost reasoning
Measured savings or credible resource accounting
Weak answer signals
Equating frugality with chronic understaffing
Ignoring reliability or future maintenance costs
Earn Trust
Build credibility through candor, listening, reliable commitments and respectful correction.
Practice questions for SDE II
Tell me about rebuilding trust after a mistake.
Describe feedback that was uncomfortable but useful.
Tell me about resetting expectations with stakeholders when your delivery estimate proved wrong.
Follow-ups: What did you communicate, to whom and when? How did you demonstrate that you understood the other perspective? What changed beyond your explanation or apology?
Strong answer signals
Candid communication backed by action
Respectful disagreement and accountability
Weak answer signals
A polished apology with no behavior change
Claiming trust while withholding material bad news
Dive Deep
Connect high-level symptoms to detailed evidence and distinguish causes from correlations.
Practice questions for SDE II
Tell me about finding the real cause of a confusing problem.
Describe a time a metric or accepted explanation was misleading.
Tell me about tracing a production issue across logs, metrics, data and code.
Follow-ups: What competing hypotheses did you test? Which observation ruled out an attractive explanation? How did you verify the fix and prevent a false conclusion?
Strong answer signals
A traceable diagnostic sequence
Evidence linking the cause to the outcome
Weak answer signals
A lucky guess presented as a method
A flood of details without a causal explanation
Have Backbone; Disagree and Commit
Challenge a decision constructively, then support a resolved direction while remaining candid about material new evidence.
Practice questions for SDE II
Tell me about disagreeing with a consequential decision.
Describe supporting a decision after your preferred option was rejected.
Tell me about disagreeing with your manager or a stakeholder on a delivery or design tradeoff.
Follow-ups: What evidence supported the other side? Who owned the final decision, and how was it made? What would justify reopening the decision rather than continuing the debate?
Strong answer signals
Respectful challenge with alternatives
Visible commitment after resolution
Weak answer signals
Compliance without ever stating the concern
Continuing to undermine an agreed decision
Deliver Results
Produce a useful outcome despite obstacles while maintaining necessary quality and transparency.
Practice questions for SDE II
Tell me about delivering an important commitment under difficult constraints.
Describe a goal you missed and how you handled the consequences.
Tell me about delivering a release when a dependency, estimate or requirement changed materially.
Follow-ups: What was the original commitment and what actually shipped? Which tradeoffs or scope changes were explicit? How did you separate your contribution from external factors?
Strong answer signals
A concrete outcome with a credible baseline
Transparent tradeoffs and lessons
Weak answer signals
Only describing effort or long hours
Quietly changing the success criterion after the fact
Strive to be Earth’s Best Employer
Make work safer, more inclusive and more sustainable through actions within your actual scope.
Practice questions for SDE II
Tell me about making a team environment more effective for someone whose needs were being missed.
Describe improving an unsustainable way of working.
Tell me about reducing an unhealthy on-call burden or improving how a team learns from mistakes.
Follow-ups: Whose perspective did you seek before acting? What concrete practice changed? How did you know the improvement lasted?
Strong answer signals
A specific inclusion, safety or sustainability action
Evidence beyond good intentions
Weak answer signals
Generic statements about being kind
Speaking for affected people without listening
Success and Scale Bring Broad Responsibility
Consider the wider consequences of technical choices and manage risks that grow with reach.
Practice questions for SDE II
Tell me about noticing an unintended consequence of a product or technical decision.
Describe balancing an immediate benefit with a broader responsibility.
Tell me about adding a safeguard after identifying how a service could harm users or expose sensitive information.
Follow-ups: Who outside the immediate team could be affected? What tradeoff did the safeguard introduce? How did you monitor for harms or unintended effects after launch?
Strong answer signals
A concrete affected group and risk mechanism
Proportionate mitigation with follow-through
Weak answer signals
A broad moral claim disconnected from your work
Assuming growth makes every outcome beneficial
Keep the technical-problem contact accessible and report an interruption promptly instead of silently losing interview time.
No. Amazon says the choice does not affect application evaluation. You can change the preference in the profile or invitation and can ask the interviewer to stop recording during the interview.
Contact the scheduling or recruiting contact as soon as possible, give clear availability with time zones and follow the official scheduling instructions. Do not wait for the meeting time to report the conflict.
My assessment or interview link is missing or does not open.
Check the invitation and spam folder, then contact the recruiter, coordinator or support contact named in the instructions. Include the role/job ID, deadline and a concise description of the problem; do not use an unofficial replacement link.
Tell the interviewer or coordinator immediately, record what failed and when, and ask how they want to continue or reschedule. Preserve assessment integrity and do not add an unapproved tool while troubleshooting.
Tell recruiting promptly and provide the real date. Amazon’s university FAQ invites candidates to share a competing deadline, but an expedited process is not guaranteed.
How many interviews are scheduled, and are HLD and LLD separate?
Does a technical screen precede the loop for this requisition?
Which design tools and coding environment will be used?
After the interview
Interviewers submit feedback for debrief and recruiting communicates the outcome or next evaluation step. Published response-time goals are useful follow-up points, not guarantees.
Amazon’s interview-process FAQ states a goal of an update within two business days after a phone interview and within five business days after a loop.
If the stated window passes, send one concise follow-up with the role, job ID and interview date.
Further evaluation may be requested when the team needs more evidence; ask what the next session covers instead of interpreting it as an automatic result.
If the role closes, ask whether a similar open role is being considered and whether additional interviews are needed. No automatic transfer or preserved offer is promised.
If team matching or team fit is unresolved, ask about responsibilities, success in the first months, engineering ownership, technical challenges, on-call expectations and working arrangement.
Do not assume a worldwide reapplication cooldown. Ask recruiting what applies to the role and hiring program.
Community-submitted experiences. These are separate from the curated official guidance and historical candidate accounts cited throughout the research guide.
No reviewed public Amazon interview experiences are published yet.
Use Amazon’s guidance for the published process. Candidate accounts and independent guides add preparation ideas; they cannot establish your interview schedule. Core official process pages checked September 14, 2026.