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2988 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 areas2988 Architecture Fundamentals91 Distributed Systems111 Data Architecture100 Cloud Architecture97 Networking96 API & Integration Architecture97 Reliability & Resilience99 Observability92 Performance & Capacity Engineering100 Security Architecture105 Cost Architecture & FinOps102 Business Architecture103 Architecture Communication102 Enterprise Architecture100 Legacy Modernization102 AI-Era Architecture106 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

4 questions in Message Formats.

  1. Message Formats intermediate

    A marketplace of eBay's kind exposes 64-bit listing ids over a JSON API. A partner's browser-based integration reports that about one listing in a thousand cannot be fetched - the id it sends differs from the one it received in the last two or three digits. The server logs show a valid request for a listing that does not exist. What is happening?

    3 min answer ebayjsonieee-754identifiers
  2. Message Formats intermediate

    A mobile client sends event times as "2027-03-28T02:30:00" with no offset. Nightly reporting has always been slightly off for European users, and on one Sunday in March about 40 minutes of events vanish from the daily rollup while a different Sunday in October shows some events twice. Diagnose it.

    3 min answer timestampsrfc3339time-zonesdst
  3. Message Formats intermediate Multiple choice

    A telemetry platform ingests billions of events daily from customer agents. Which message format should the wire protocol use, and what does the choice affect beyond size?

    2 min answer serialisationprotobufschema-evolutioncompression
  4. Message Formats intermediate Multiple choice

    An events pipeline carries 2 billion events a day. Each event is JSON with 25 fields whose names average 14 characters. Roughly how many bytes a day go on field names alone, before compression?

    2 min answer message formatsjsonprotobufcompression