Distributed Systems
31 bites tagged Distributed Systems — interview questions with model answers, and 60-second explainers.
How do you adapt ML training for spot instance interruptions?
Tests resilience under preemption. Strong answers cover frequent checkpoints to durable storage, SIGTERM handling, idempotent retries with budgets, and compute-state separation. Red flag: saving checkpoints only on local ephemeral disks or solely at epoch end.
Propose an architectural solution for contended GPU training resources
Tests multi-tenant GPU scheduling design at scale. Great answers tier jobs by checkpointability, apply quota-based preemption, mix spot and on-demand instances, and use MIG or time-slicing to bin-pack. Red flag: buying GPUs without scheduling logic.
How would you implement a simple feature flag system?
Tests runtime config separation and distributed hygiene. Outline: control service, datastore, API, SDK, and update mechanism; local evaluation with cached state; short-lived flags. Red flag: static config files requiring redeployment are not feature flags.
How would you implement a timezone-safe, tamper-proof offer countdown?
Tests distrust of the client and server-side UTC enforcement. Outline: server owns canonical end time; client syncs clock offset to render remaining time; checkout re-validates expiry. Red flag: using local Date.now or localStorage.
Leaderless Replication: No Master, No Bottleneck
Leaderless replication lets any node accept writes, skipping a single leader bottleneck. Systems like Dynamo stay available during partitions, reconciling conflicts with vector clocks later.
How do you fulfill a GDPR erasure request across microservices?
Log the request, emit a durable erasure event, let each service delete or anonymize locally, then reconcile. Distributed data governance and eventual consistency.
Architect email subject line A/B testing for a large user base
Tests distributed systems and statistical rigor. Covers deterministic user bucketing, isolated variant delivery, deduplicated tracking, and pre-powered significance. Red flag: daily re-randomization or using open rate without confidence intervals.
Get Distributed Systems bites daily.
Five a day, five minutes, offline. With quizzes so it sticks.
Open testing — you’ll join as an early tester.