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Quiz

2777 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 areas2777 Architecture Fundamentals81 Distributed Systems101 Data Architecture90 Cloud Architecture87 Networking86 API & Integration Architecture87 Reliability & Resilience99 Observability92 Performance & Capacity Engineering90 Security Architecture95 Cost Architecture & FinOps92 Business Architecture93 Architecture Communication91 Enterprise Architecture100 Legacy Modernization92 AI-Era Architecture96 Software Architecture & Engineering93 Architecture Patterns84 Architecture Decision-Making91 The Architect's Meta-Skills92 Delivery & Release Engineering93 Platform Engineering & Developer Experience92 Testing & Quality Architecture102 Data Platform Architecture98 Streaming & Real-Time Data93 Data Governance & Semantics91 Frontend & Experience Architecture91 Edge, Mobile & IoT88 Regulatory & Data Protection Architecture99 Assurance, Audit & Model Risk98
Difficulty Any beginner intermediate advanced

2777 questions.

  1. Database Performance advanced

    A query that ran in 40 ms has taken 40 seconds since Tuesday. The query and the code are unchanged. What happened?

    2 min answer databasequery-planstatisticsdiagnosis
  2. Database Performance advanced

    A search product must choose between indexing throughput and query latency on the same hardware. How should the trade be made explicit and managed?

    2 min answer meilisearchsearchindexingcontention
  3. Database Performance advanced

    A voucher-redemption feature creates a single hot row that thousands of buyers hit in the same second. Compare row-level locking, optimistic concurrency, bucketed counters and an in-memory reservation service.

    3 min answer hot-rowcontentionoptimistic-concurrencyreservation
  4. Database Performance advanced

    An application with ten million users has a database bottleneck. In what order do you intervene, and why is sharding last?

    2 min answer databasescalingshardingreplicas
  5. Database Performance advanced

    Review this proposal. A team has six slow queries against a 400 GB table taking 40,000 writes a minute, and proposes adding six indexes, one per query. What would you remove, what would you change, and what would you keep?

    3 min answer indexeswrite amplificationbuffer poolquery plans
  6. Dead Letter Handling beginner Multiple choice

    A platform team sets one default for every stream consumer: retry a failing record three times then route it to a dead-letter topic and carry on. The ledger team's consumer derives account balances from ordered per-account events. What trade-off does that default make on their behalf and what should they run instead?

    3 min answer dead letterorderingavailabilitycorrectness
  7. Dead Letter Handling intermediate

    A streaming pipeline sends failed messages to a dead-letter queue. What makes that a real control rather than a data-loss mechanism?

    2 min answer segmentdead-letterpoisonownership
  8. Dead Letter Handling intermediate

    How should unprocessable messages be handled, and what makes dead-letter handling useful rather than a graveyard?

    2 min answer dead-letterpoison-messagesreplayvisibility
  9. Dead Letter Handling intermediate

    You find 40,000 messages in a dead letter queue, the oldest from seven months ago. Nobody knew. What do you fix?

    2 min answer messagingoperationsdata-loss
  10. Debugging Distributed Systems advanced

    A collaborative editing platform receives a report that one document occasionally shows different content to different users, but it cannot be reproduced. How do you investigate a rare, non-deterministic, distributed bug?

    2 min answer debuggingnon-determinismdistributedforensics
  11. Debugging Distributed Systems intermediate

    A deployment completes successfully. Twenty minutes later latency has tripled, but only on new instances. Diagnose.

    2 min answer deploymentcold-startdiagnosiscaching
  12. Debugging Distributed Systems advanced

    A platform of 40 services has logs only, and incidents take hours to diagnose. Design the observability strategy and its rollout order.

    2 min answer observabilitytracingmetricsrollout