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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

33 questions in Performance & Capacity.

  1. Profiling & Optimisation intermediate

    A team has profiled a service and found the top three functions by CPU time. Why is optimising them often the wrong next step?

    2 min answer profilingoptimisationamdahlmeasurement
  2. Queueing Theory intermediate

    A capacity review shows services running at 85% CPU. Finance suggests raising it to 95% to save money. What is your response?

    2 min answer capacitylatencycost
  3. Soak Testing intermediate

    A platform passes every load test yet degrades after several days of continuous operation. What class of problem is this, and what testing finds it?

    2 min answer soak-testingmemory-leaksresource-exhaustionendurance
  4. Soak Testing intermediate

    A service is restarted nightly by a cron job and nobody remembers why. What do you suspect and how do you confirm it?

    2 min answer soak-testingmemory-leakresource-leaktrends
  5. Soak Testing intermediate

    A service performs well in load tests and degrades after several days in production. What class of problem is this, and how is it found before release?

    2 min answer credsoak-testingleaksfragmentation
  6. Soak Testing intermediate

    A team proposes replacing its weekly 48-hour soak with a 30-minute soak in every pipeline run. Review the proposal. What would you keep, what would you change, and what can a 30-minute run never find?

    3 min answer soak-testingdriftregression-gatememory
  7. Stress Testing intermediate

    What is the purpose of stress testing beyond load testing, and what should a communication platform learn from deliberately breaking itself?

    2 min answer stress-testingbreaking-pointdegradationrecovery
  8. Throughput intermediate

    A pipeline moves from writing records one at a time to batches of 500, and throughput rises roughly twentyfold. What has been given up, and at what batch size does the trade stop paying?

    2 min answer batchingthroughputlatencyblast radius
  9. Throughput intermediate

    Throughput has plateaued and adding instances does not help. What are the candidate bottlenecks and how do you identify which?

    2 min answer throughputbottlenecksaturationscaling