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Quiz

2827 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 areas2827 Architecture Fundamentals91 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-Making101 The Architect's Meta-Skills92 Delivery & Release Engineering103 Platform Engineering & Developer Experience92 Testing & Quality Architecture102 Data Platform Architecture98 Streaming & Real-Time Data93 Data Governance & Semantics91 Frontend & Experience Architecture101 Edge, Mobile & IoT98 Regulatory & Data Protection Architecture99 Assurance, Audit & Model Risk98
Difficulty Any beginner intermediate advanced

2827 questions.

  1. Fault Isolation intermediate Multiple choice

    Fastly's June 2021 incident saw a valid customer configuration trigger a latent bug from a May deployment, returning errors across most of its network for under an hour. You run a multi-tenant API where one tenant's input can reach a latent defect in shared code. Which isolation approach limits the damage?

    4 min answer fastlycellsshuffle shardingblast radius
  2. Fault Isolation advanced Multiple choice

    What is the single highest-value fault isolation mechanism, and why is it usually missing?

    2 min answer bulkheadspoolscascading-failurecells
  3. Feature Flags advanced

    A codebase has 300 feature flags. What went wrong and how do you fix it without breaking anything?

    2 min answer feature-flagstechnical-debtlifecyclecombinatorics
  4. Feature Flags intermediate

    A codebase has accumulated hundreds of feature flags, many years old. What went wrong, and what discipline prevents it?

    2 min answer sentryfeature-flagslifecyclecomplexity
  5. Feature Flags advanced

    A feature flag controls a pricing rule. Finance asks who changed it, when, what the previous value was, and which orders were priced under the new value. Walk me through what that requirement does to the design of your flag system.

    3 min answer feature flagsconfigurationauditpricing
  6. Feature Flags intermediate

    A platform has accumulated hundreds of feature flags and nobody knows which are safe to remove. What went wrong, and what practice prevents it?

    2 min answer feature-flagsdebtlifecyclecomplexity
  7. Feature Flags intermediate

    A team adopts feature flags enthusiastically and two years later the codebase is full of them. What went wrong, and how should flags be managed as a lifecycle?

    3 min answer feature-flagstechnical-debttestinglifecycle
  8. Feature Flags advanced

    Interview. Your incident runbook says "disable the recommendation service with the feature flag". Walk me through what has to be true for that instruction to work during a real incident, and how you would prove it.

    3 min answer feature-flagskill-switchincident-responsestaleness
  9. Feature Flags intermediate

    Your feature flag service becomes unavailable. What happens to the fleet, and what should happen?

    2 min answer flagscontrol-planefallbackavailability
  10. Feature Freshness advanced

    ByteDance's Monolith paper (ORSUM at RecSys 2022) describes a collisionless embedding table for a recommender trained on the interaction stream, where new user and item ids arrive continuously so the key space has no ceiling. What bounds the memory, and what does each bound cost in model quality?

    3 min answer bytedancemonolithembeddingsonline training
  11. Feature Freshness advanced

    ByteDance's Monolith paper (RecSys workshop 2022) describes training recommendation models on user feedback as it arrives rather than in nightly batches, and states that system reliability was deliberately traded for real-time learning. What does that trade actually look like in the pipeline, and when is a nightly batch the better engineering decision?

    2 min answer bytedanceonline trainingembeddingsfreshness
  12. Feature Freshness advanced

    Delivery ETAs are computed by a model using live traffic and restaurant load. The model's features are computed in batch overnight. What is wrong?

    2 min answer doordashmlfeaturesskew