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Quiz

126 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 areas126 Architecture Fundamentals2 Distributed Systems26 Data Architecture23 Cloud Architecture19 Networking3 API & Integration Architecture1 Reliability & Resilience4 Observability3 Performance & Capacity Engineering3 Security Architecture16 Cost Architecture & FinOps3 Business Architecture2 Architecture Communication2 Enterprise Architecture1 Legacy Modernization2 AI-Era Architecture3 Software Architecture & Engineering3 Architecture Patterns3 Architecture Decision-Making6 The Architect's Meta-Skills1
Difficulty Any beginner intermediate advanced

23 questions in Data Architecture.

  1. Data Warehousing advanced

    A finance report double-counts revenue after a new fact table is added. What is the likely modelling error?

    2 min answer warehousegrainfan-outdimensional-modelling
  2. ETL & ELT intermediate

    A nightly pipeline failed halfway and the retry produced duplicate rows. Walk me through fixing this properly.

    2 min answer idempotencypipelinesbackfillcorrectness
  3. Event Sourcing advanced

    A team wants event sourcing for a new order service, citing audit requirements. What do you recommend?

    2 min answer event-sourcingauditdecision-making
  4. Indexing intermediate

    A table has 14 indexes and writes have become slow. How do you decide which to remove?

    2 min answer indexingwrite-performancereview
  5. NoSQL Stores intermediate

    A team wants to move a workload from PostgreSQL to a document store because "the schema keeps changing". What do you ask?

    2 min answer nosqlschemamigrationdecision-making
  6. Polyglot Persistence advanced

    Four services want four different databases: Postgres, MongoDB, Cassandra and Neo4j. What do you say?

    2 min answer polyglotoperationsdecision-makingstandards
  7. Polyglot Persistence advanced

    Your search index and your database disagree — some products appear in search that were deleted, and some new ones never appear. How do you make this reliable?

    2 min answer consistencyindexingoutboxreconciliation
  8. Query Optimisation advanced

    A query that ran in 50ms for two years now takes 90 seconds. Nothing was deployed and the data volume grew normally. What happened?

    2 min answer plannerstatisticsplan-flipdiagnosis
  9. Relational Modelling intermediate

    A team proposes storing the customer's address on every order row "so order history is accurate". Is that denormalisation or a modelling error?

    2 min answer normalisationmodellinghistorytemporal
  10. Replication advanced

    Users report seeing stale data intermittently. Replication lag is normally under a second but spikes to minutes twice a day. How do you handle it?

    2 min answer replicationlagroutingconsistency
  11. Streaming Data advanced

    A streaming aggregation reports lower totals than the batch job it replaced. Both read the same source. What is likely happening?

    2 min answer streamingwatermarkslate-dataevent-time