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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 Migration advanced

    A product must move its primary data store while remaining live, with no acceptable data loss. What is the migration sequence, and where do these go wrong?

    2 min answer database-migrationdual-writeverificationcutover
  2. Database Migration beginner Multiple choice

    A team plans to move 2.5 TB to a new database by taking the application offline at 22:00 on Saturday, restoring a backup into the new store, and switching over by 08:00 Sunday. The data copies fine in a test at one tenth the volume. Why does this plan usually fail before it is executed?

    3 min answer cutoverrestorerollbackmaintenance window
  3. Database Migration advanced

    An online schema change is needed on a billion-row MySQL table with zero downtime. Compare trigger-based, binlog-based and native approaches, and describe how the change is gated and reverted.

    3 min answer schema-changegh-ostpt-online-schema-changemysql
  4. Database Migration advanced

    Notion sharded its Postgres data into 480 logical shards across 32 physical databases in 2021 and then in 2023 spread the same 480 logical shards across 96 databases, with no change to the routing logic. What did the 2021 decision buy, what did the 2023 move still cost, and where would copying the number be a mistake?

    3 min answer notionpostgresshardingresharding
  5. Database Migration advanced

    Walk through migrating a live database to a different engine with no downtime. Where does reversibility end?

    2 min answer migrationverificationshadow-readsreversibility
  6. Database Migration Under CD advanced

    A platform gates schema changes through a reviewable, revertible "deploy request" rather than allowing direct DDL. What does this buy, and what must the mechanism provide?

    2 min answer planetscalevitessschema-changegating
  7. Database Migration Under CD intermediate

    A release must rename a heavily used database column and ships tonight. The team proposes doing the rename in the deployment. What is wrong, and what do you propose?

    2 min answer migrationrollbackschemacontinuous-delivery
  8. Database Migration Under CD intermediate Multiple choice

    A superapp in the mould of Grab renames a column using expand and contract. The rolling deploy of the 240-pod service takes 11 minutes. A batch consumer reads a cached schema descriptor with a 1-hour TTL. A worker fleet is draining a 6-hour backlog of jobs serialised against the old shape. Mobile clients hold the old field name until users update. Roughly how long must both shapes stay correct before the contract step is safe?

    3 min answer grabexpand-and-contractschema-migrationmobile-clients
  9. Database Migration Under CD advanced

    A team deploys many times a day and must change the database schema. What discipline makes this safe?

    2 min answer migrationsexpand-contractrollbackbackfill
  10. Database Migration Under CD intermediate

    A team deploys several times a day and needs to change a database schema. What sequence prevents downtime, and which step is skipped?

    2 min answer chargebeemigrationexpand-contractbackfill
  11. Database Migration Under CD advanced Multiple choice

    You deploy at 14:00. At 14:20 error rates spike. The release included a migration that dropped a column. What do you do, and what should have been different?

    2 min answer rollbackmigrationincident
  12. Database Performance advanced

    A multi-tenant platform's database performance is fine for most tenants and severely degraded for a few. What are the likely causes and their fixes?

    2 min answer database-performancemulti-tenancystatisticsplans