DoorDash System Design interview questions focus on high-scale, real-time logistics problems: dispatch/matching, live tracking, ETA estimation, and catalog/search at regional scale. Distinctive to DoorDash is the emphasis on geo-partitioning, event-driven pipelines, idempotent operations, and operational resilience during peak windows. Interviewers evaluate how you scope a product-aligned problem, estimate load and latency, propose APIs and data models, and justify trade-offs between consistency, cost, and availability. Expect a 45–60 minute whiteboard or virtual-board session where clarifying assumptions, back-of-the-envelope capacity estimates, and a clear failure/recovery plan matter as much as your architecture diagram. For effective interview preparation, practice framing ambiguous prompts into measurable requirements, sketch end-to-end data flow, and drill into one component to show depth—caching, streaming, sharding, or monitoring. Use mock interviews to tighten communication and rehearse common DoorDash-style prompts (delivery assignment, real-time location, and search/indexing). Conclude designs with operational concerns: retries, observability, SLAs, and deployment trade-offs. That narrative shows you can build for both product needs and production realities.