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2908 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 areas2908 Architecture Fundamentals91 Distributed Systems101 Data Architecture90 Cloud Architecture87 Networking86 API & Integration Architecture87 Reliability & Resilience99 Observability92 Performance & Capacity Engineering100 Security Architecture95 Cost Architecture & FinOps102 Business Architecture103 Architecture Communication102 Enterprise Architecture100 Legacy Modernization92 AI-Era Architecture96 Software Architecture & Engineering93 Architecture Patterns94 Architecture Decision-Making101 The Architect's Meta-Skills102 Delivery & Release Engineering103 Platform Engineering & Developer Experience102 Testing & Quality Architecture102 Data Platform Architecture98 Streaming & Real-Time Data103 Data Governance & Semantics91 Frontend & Experience Architecture101 Edge, Mobile & IoT98 Regulatory & Data Protection Architecture99 Assurance, Audit & Model Risk98
Difficulty Any beginner intermediate advanced

5 questions in Connection Pooling.

  1. Connection Pooling intermediate

    A checkout handler takes a pooled database connection at the start of the request and releases it at the end. In between it calls a partner API that takes 300 ms at p50. Traffic is 400 requests per second and the SQL itself takes 15 ms. Roughly how large must the pool be and what is the better answer?

    3 min answer connection-poolinglittles-lawthird-partypool-sizing
  2. Connection Pooling intermediate

    A service scales its application instances from 20 to 200 and the database begins refusing connections. What happened, and what is the correct architecture?

    2 min answer connection-poolingproxyscalingdatabase-limits
  3. Connection Pooling advanced

    A service under load has high latency and low CPU. The team increases the database connection pool and it gets worse. Why?

    2 min answer sharechatconnection-poolcontentionqueueing
  4. Connection Pooling intermediate

    A service works fine at 10 instances. At 60 instances during a peak, the database starts refusing connections. Explain the arithmetic.

    2 min answer poolsscalingdatabases
  5. Connection Pooling beginner

    Why does putting a connection pool in front of a database make a service faster when the database does exactly the same query work either way?

    3 min answer connection-poolingtls-handshakepostgresconcurrency