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Quiz

2667 questions of the kind that actually get asked — in interviews, in architecture review boards, and by the person who has to run the thing at 3 AM. Every answer states the trade-off rather than the slogan, and says when the obvious choice is the wrong one.

All areas2667 Architecture Fundamentals81 Distributed Systems101 Data Architecture90 Cloud Architecture87 Networking86 API & Integration Architecture78 Reliability & Resilience88 Observability81 Performance & Capacity Engineering90 Security Architecture95 Cost Architecture & FinOps92 Business Architecture93 Architecture Communication91 Enterprise Architecture91 Legacy Modernization92 AI-Era Architecture86 Software Architecture & Engineering84 Architecture Patterns84 Architecture Decision-Making91 The Architect's Meta-Skills92 Delivery & Release Engineering93 Platform Engineering & Developer Experience92 Testing & Quality Architecture90 Data Platform Architecture88 Streaming & Real-Time Data93 Data Governance & Semantics81 Frontend & Experience Architecture91 Edge, Mobile & IoT88 Regulatory & Data Protection Architecture90 Assurance, Audit & Model Risk88
Difficulty Any beginner intermediate advanced

53 questions in Performance & Capacity.

  1. Tail Latency advanced

    A request fans out to 100 services in parallel. Each responds within 10 ms for 99% of calls. What fraction of user requests are slow, and what do you do?

    2 min answer fan-outlatencyhedgingarithmetic
  2. Tail Latency advanced

    A video platform's request path fans out to twenty backend services in parallel. Each has a p99 of 50 ms. Why is the overall p99 far worse than 50 ms, and what fixes it?

    2 min answer tail-latencyfan-outhedgingamplification
  3. Tail Latency advanced

    You add hedged requests to cut tail latency. It works well, then during a traffic peak the service collapses. Explain.

    2 min answer hedgingoverloadlatency
  4. Throughput advanced

    A capacity test on a live-streaming platform at Twitch scale plateaus at 18000 requests per second however many application instances are added. Fleet CPU is 45%, the database is at 20%, and no queue is growing. What do you check before reporting that ceiling?

    3 min answer load-testingclosed-loopload-generatorephemeral-ports
  5. Throughput advanced

    A recommendation platform must ingest billions of interaction events daily without the ingestion path becoming a bottleneck. Which throughput techniques matter most, and which common approach limits scale?

    2 min answer throughputbatchingpartitioningingestion