System design interview guides

How the round works, how it is scored, and how to prepare for it at your level.

• How to prepare for a system design interviewWhat the system design round measures, a minute-by-minute plan for 45 minutes, what changes from mid to senior to staff, the concepts to know, and a four-week practice plan.
• System design cheat sheetOne page for system design interviews: the numbers to know, estimation shortcuts, which building block solves which problem, and the trade-off each one brings.
• Machine learning system design interviewA machine learning system design interview asks you to design the complete path from raw data to predictions and measurable product outcomes.
• System design interviews for beginnersA system design interview asks you to turn an open-ended product requirement into a workable architecture and explain its trade-offs.
• A system design interview templateA useful system design interview template is: clarify requirements, estimate the workload, define APIs and data, sketch a baseline, explore the hardest parts, and test failures.
• How system design interviews are scoredSystem design interviews are scored on how you frame the problem, drive the discussion, build a coherent design, and defend it under deeper questioning, not just on the architecture you draw.
• The senior system design interviewA senior system design interview tests whether you can turn an ambiguous prompt into a prioritized problem, build a coherent design, and defend it under failure and scale.
• The staff engineer system design interviewThe staff engineer system design interview tests whether you can identify the hardest constraint, build the smallest coherent design around it, and defend that design through detailed failure and capacity questions.
• The product architecture interviewA product architecture interview asks you to turn a user-facing product into a working technical design, including APIs, data models, service boundaries, and important user flows.
• The API design interviewAn API design interview tests whether you can define a clear contract between clients and a system, including what happens during retries, concurrent updates, and failures.
• Low-level design vs high-level designHigh-level design (HLD) explains how a system's major components work together to meet requirements for scale, reliability, and correctness.
• Distributed systems interview questionsDistributed systems interview questions test how you preserve correctness when machines communicate over unreliable networks.