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Quiz

2627 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 areas2627 Architecture Fundamentals81 Distributed Systems101 Data Architecture90 Cloud Architecture77 Networking86 API & Integration Architecture78 Reliability & Resilience88 Observability81 Performance & Capacity Engineering90 Security Architecture85 Cost Architecture & FinOps82 Business Architecture93 Architecture Communication91 Enterprise Architecture91 Legacy Modernization82 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

84 questions in Architecture Patterns.

  1. Competing Consumers advanced

    A team uses competing consumers to scale processing and discovers that ordering guarantees are broken. What happened, and what are the options?

    2 min answer segmentcompeting-consumersorderingpartitioning
  2. Competing Consumers advanced

    At 14:02 a consumer group of twelve workers is draining a partitioned order-events topic at 9,000 messages a second. By 14:07 throughput is zero while every worker is running and its health check passes, and queue depth is climbing. At 14:12 throughput returns for forty seconds and then stops again. The pattern repeats. What failed, and which design decision allowed it?

    3 min answer kafkaconsumer grouprebalancepoison message
  3. CQRS advanced

    A classifieds and auction marketplace at eBay's listing volume runs CQRS - writes to Postgres and a search-shaped read model built from an append-only change log that now holds 1.2 billion events across 24 partitions. A projection bug has been live for nine days. Work out roughly how long a full rebuild takes and say what that number decides.

    3 min answer cqrsprojectionrebuildread model
  4. CQRS advanced

    A live platform's read requirements differ sharply from its write model. What evidence justifies CQRS, and what obligation does it create?

    2 min answer cqrsread-modelprojectionsrebuild
  5. CQRS advanced

    A team proposes CQRS with event sourcing for a new internal admin tool because the patterns are considered scalable. Evaluate.

    3 min answer cqrsevent-sourcingover-engineeringtradeoffs
  6. CQRS advanced

    A team proposes CQRS with event sourcing for a new service. How do you evaluate the proposal?

    2 min answer cqrsevent-sourcingcomplexitydecision
  7. Event-Driven Architecture advanced

    A platform adopts event-driven architecture broadly and finds debugging and reasoning much harder. When is event-driven the wrong choice?

    2 min answer event-drivencouplingdebuggingobligations
  8. Event-Driven Architecture advanced

    A team proposes routing every internal workflow through an event-streaming platform because it is scalable and decoupled. What questions do you ask and when is a simpler mechanism correct?

    3 min answer event-drivenkafkaover-engineeringtradeoffs
  9. Event-Driven Architecture intermediate

    Before 2017 every consumer of published content at The New York Times integrated with each producing system's own API and bootstrapped its history by calling those APIs. The 2017 publishing pipeline replaced that with one Kafka log. What changed about the cost of adding the eleventh consumer, and about who pays for a backfill?

    3 min answer new york timeskafkaintegration costbackfill
  10. Event-Driven Architecture advanced

    Review this design. Every service publishes one event type per aggregate - OrderChanged carries the whole order document plus a changeType string. Eleven consumers subscribe and each begins with a switch on changeType, ignoring types it does not care about. What would you remove, what would you change, and what would you leave alone?

    3 min answer event-drivenevent granularitycouplingschema
  11. Event Sourcing advanced

    A ledger service rebuilds its balance projection from the event log into a new store. The rebuilt balances differ from the live ones for about 0.3% of accounts, all of them accounts with activity during two specific weeks last year. The event log has not been modified. What went wrong, and which design decision allowed it?

    3 min answer event sourcingreplaydeterminismprojections
  12. Event Sourcing advanced

    A platform considers event sourcing for auditability. What is the permanent cost teams underestimate, and what is the cheaper alternative?

    2 min answer event-sourcingauditschema-evolutionalternatives