Senior / SDE III - 90 Day DSA Roadmap

Use 90-day pacing in the Plan Builder

1. 1
   Days 1–7

   Baseline and language#

   Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Goals

   • Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Focus

   concept

   Day 1: Refresh Python interview contractsDay 2: Complexity: name the work you are counting
2. 2
   Days 8–28

   Foundations and core repair#

   Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Goals

   • Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Focus

   conceptarrays-hashingtwo-pointersbinary-searchlinked-list

   Day 8: Recursion: make each call's contract explicitDay 9: Correctness: explain why the algorithm must workDay 10: Representation: decide what every value meansDay 11: Arrays & HashingDay 12: Two PointersDay 13: Binary SearchDay 15: Linked List
3. 3
   Days 29–49

   Structures and patterns#

   Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Goals

   • Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Focus

   treesheap-priority-queuebacktrackingintervalsgraphsone-d-dp

   Day 29: TreesDay 30: Heap / Priority QueueDay 31: BacktrackingDay 32: IntervalsDay 33: GraphsDay 34: 1-D Dynamic Programming
4. 4
   Days 50–64

   Variants and selected extensions#

   Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Goals

   • Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Focus

   practiceconcept

   Day 50: Earliest finishes in a dependency planDay 51: Nearest declared grid exitDay 52: Component count after each connectionDay 53: Minimum spanning forestDay 54: Minimum dictionary tokenizationDay 55: Merge timestamped streamsDay 57: Integer arithmetic and coordinate reasoning
5. 5
   Days 65–76

   Mixed and confirmed-format practice#

   Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Goals

   • Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Focus

   review

   Day 65: Clarify a changed contract before coding
6. 6
   Days 77–85

   Mocks and targeted recovery#

   Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Goals

   • Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Focus

   mockreview

   Day 78: Senior - Ambiguous Reachability ContractDay 79: Turn one failure into a regression test
7. 7
   Days 86–90

   Consolidation and buffer#

   Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Goals

   • Handle repeated follow-ups, review code for correctness and maintainability, and add only domain-relevant extensions after confirmed-format and cross-track commitments fit.

   Focus

   review

   Day 86: Review and transfer from the mistake logDay 87: Rehearse the final checklist without cramming