DoorDash Coding Interview Questions
32 DoorDash coding interview problems with full optimal solutions — 3 easy, 21 medium, 8 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an DoorDash interviewer values, and a FAQ section.
Showing 3 problems of 32
- #21easyfoundational
21. Number of Islands
Count connected land zones in a grid — Doordash uses this BFS/DFS classic to see if you can reason about delivery coverage zones and autonomous map-segmentation logic under time pressure.
- #22easyfoundational
22. Merge Intervals
Collapse overlapping time windows into the fewest spans — Doordash uses this interval pattern directly in delivery time-window consolidation and Dasher shift-block scheduling.
- #23easyfoundational
23. Valid Parentheses
Validate bracket nesting with a stack — Doordash treats this as a warmup for stack reasoning, which surfaces in their order-processing pipeline and nested-menu parsing logic.
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