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

90 questions in Data Architecture.

Quiz

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

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?

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

An endpoint's p99 is 4 seconds. The database's slow query log is empty and CPU is low. What is happening?

In a multi-tenant platform where every tenant's data shares the same physical tables and tenants differ in size by orders of magnitude, why do query plans that are optimal for one tenant become pathological for another - and what is the fix?

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

A team wants to store a product's variable attributes as a JSON column rather than modelling them as tables. When is that right and what is given up?

An issue-tracking product lets every customer define custom fields, workflows and screens. Which data model should the platform use for custom fields?

A marketplace seller edits a listing and is immediately shown the old version, because the read went to a replica. What are the options, and how should the choice be made?

An analytics platform's database is write-bound rather than read-bound. The team adds read replicas and nothing improves. Why, and what should be done instead?

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?

Users report their own profile edits sometimes vanish immediately after saving. Replication lag averages 300 ms. Explain and give three fixes of increasing cost.