Quiz

2627 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 areas2627 Architecture Fundamentals81 Distributed Systems101 Data Architecture90 Cloud Architecture77 Networking86 API & Integration Architecture78 Reliability & Resilience88 Observability81 Performance & Capacity Engineering90 Security Architecture85 Cost Architecture & FinOps82 Business Architecture93 Architecture Communication91 Enterprise Architecture91 Legacy Modernization82 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

101 questions in Distributed Systems.

Quiz

Where does consensus belong in an architecture, and where is it a mistake?

A crypto exchange must decide which operations require strong consistency and which can be eventually consistent. Where should the line be drawn, and what is the cost of drawing it wrong in each direction?

A food-delivery platform must match orders to nearby couriers while supply and demand change every few seconds. Which information needs strong consistency, which can be stale, and how should dispatch handle a courier who accepted a job while their availability record was out of date?

After a user updates their profile, the page sometimes shows the old value. The team says this is normal eventual consistency. Is that acceptable?

For a shopping cart at very large scale, would you choose a strongly consistent store or an always-writeable one with conflict resolution?

Two people are editing the same page in a collaborative workspace. One loses connectivity for several minutes while continuing to type, then reconnects. What should happen, and what consistency guarantee is actually required?

A media platform uses a distributed lock to stop two workers rendering the same expensive export. Workers sometimes crash while holding the lock, and occasionally two workers process the same job anyway. Diagnose both problems and redesign.

A team proposes a distributed lock to stop two workers processing the same transaction. Workers sometimes crash or pause while holding the lock. What is the safer design, and when is a lock genuinely necessary?

A team uses a distributed lock in a key-value store to ensure only one worker processes a job. Occasionally two workers process the same job. Explain.

Three designs need distributed locks: a nightly report, a per-customer state machine, and a global config reload. For each, is a lock the right answer?

A 43-second network partition caused GitHub over 24 hours of degraded service in 2018. How does a 43-second event become a day-long incident?

A card payment authorisation service runs active-active across two regions. A network partition splits them. Do you keep accepting authorisations, and what breaks either way?