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Quiz

2948 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 areas2948 Architecture Fundamentals91 Distributed Systems101 Data Architecture90 Cloud Architecture87 Networking96 API & Integration Architecture87 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

2948 questions.

  1. Observability intermediate

    A new service goes live next week. What observability must exist on day one?

    2 min answer observabilitylaunchoperations
  2. Observability advanced

    An analytics platform ingests billions of events while customers run arbitrary segmentation queries. How should the two workloads be isolated, and when should pre-aggregation be introduced?

    2 min answer posthogamplitudeingestionquery-isolation
  3. Observability advanced

    An error-tracking platform receives millions of events, many of them the same underlying problem with different stack details. How should grouping, deduplication, high-cardinality metadata and retention be designed?

    2 min answer sentrygroupingdeduplicationretention
  4. Observability advanced

    On 11 December 2024 OpenAI rolled a new telemetry service out across every Kubernetes cluster. Within about half an hour the API servers were saturated and services could no longer resolve one another; full recovery took until the evening. What turned a monitoring change into a total outage, and which of the contributing factors would you fix first?

    3 min answer openaikubernetescontrol planedns
  5. Observability intermediate

    You are designing a new service. What must be in place before it goes live so that whoever is paged at 3 AM can diagnose it without you?

    2 min answer observabilityoncallalertinglogging
  6. Observability advanced

    Your observability bill is now 40% of your compute bill. Leadership wants it cut in half without going blind. What do you cut?

    2 min answer observabilitycostcardinalitysampling
  7. Observability advanced

    p99 latency on checkout tripled overnight. Dashboards look normal, no deployment went out, and every service reports healthy. How do you find it?

    3 min answer debuggingtracinglatencydiagnosis
  8. Observability Cost advanced

    A platform's telemetry spend approaches its compute spend. Which reduction preserves diagnostic value, and which destroy it?

    2 min answer observability-costcardinalitysamplingretention
  9. Observability Cost advanced

    An observability platform's own telemetry costs have grown faster than its revenue. Which decisions reduce it without losing the ability to debug?

    2 min answer sentrygrafanatelemetry-costindexing
  10. Observability Cost advanced

    Datadog published Husky in 2022, a third-generation event store built on commodity object storage with FoundationDB holding the metadata, replacing an architecture backed by local SSDs. What forced the change, what did it buy economically, and what did it cost?

    2 min answer datadoghuskyobject-storagecolumnar
  11. Observability Cost advanced

    Telemetry is 28% of infrastructure spend on a contract billed per host and per custom metric, with 14 months left on a minimum annual commitment. The team wants to move to a self-hosted stack. Sequence the move under live traffic, and say when the saving actually starts.

    3 min answer observability costvendor exitopentelemetrycommitments
  12. Observability Cost advanced

    To stop losing the traces that matter, a team moves from 5% head sampling to capturing every span and deciding in its own collector tier, keeping 2% after the decision. Vendor ingest falls by 60%. What has the team given up, and when does that bill arrive?

    3 min answer tracingtail-samplingcollectorscross-zone