System Design Interview Questions

Practice 1,166 real System Design interview questions for 2026. Covers open-ended architecture problems from actual interviews with detailed solutions; System Design interview questions you can use for interview preparation at every seniority level, from mid-level backend roles to staff/infra interviews. System design rounds test how you scope problems, choose APIs and data models, size and shard storage, reason about latency, consistency, fault tolerance and operational costs, and trade off complexity vs. reliability. Companies that weight this category heavily include Meta, Google, and OpenAI, with Amazon and Rippling also asking system-style problems on many teams. Expect System Design to appear mid-to-late in an onsite loop as a 45–90 minute conversational whiteboard or collaborative doc exercise; interviewers score structure, technical depth, trade-off thinking, and communication. To prepare, practice a representative set of large-scale patterns, rehearse back-of-envelope scaling math, and run mock design interviews that force you to justify trade-offs under time pressure.