This is the kind of question that looks open-ended but has a lot of expected answers underneath it.
Walk through the system left-to-right, identifying failure modes and bottlenecks at each component and connection. For each, briefly mention detection, mitigation, and trade-offs. Conclude with a prioritized list of the most critical risks and how you'd address them.
Pro tip: Tie failures to business impact (e.g., revenue loss, user trust) and mention observability (metrics, tracing) to show you think beyond just fixing issues.
Trace a request from client through DNS, load balancer, service, database, and external API. Note synchronous vs asynchronous calls and critical dependencies.
For each component, list potential failures (e.g., DNS resolution failure, LB overload, service crash, DB connection exhaustion, external API downtime) and their symptoms.
Consider how one failure can trigger others (e.g., external API latency causing thread pool exhaustion, leading to service unavailability). Discuss retries, timeouts, and circuit breakers.
Suggest monitoring (health checks, metrics, tracing), redundancy (multi-AZ, caching, fallbacks), and graceful degradation for each failure mode.
Rank risks by likelihood and impact, and summarize the top 2-3 with concrete next steps, showing pragmatic prioritization.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.