Meta Site Reliability Engineer Interview Questions

I would use a backward-compatible migration plan so old and new versions can run together during rollout. A common path is to add the new schema, deploy code that can read both versions if needed, backfill data, switch reads, and then clean up the old path later. The reason I choose this approach is that it lowers downtime risk and makes rollback safer. I would also think about locking, migration size, and how to test the migration on staging data. If the interviewer wants more detail, I would discuss how I would handle partial failures during the migration.

I would first clarify the consistency requirements, because active-active designs trade off complexity against resilience. Then I would design routing, replication, conflict handling, and failover so traffic can be served from multiple regions. The reason I choose this approach is that active-active can improve availability but it needs careful handling of data consistency and user experience. I would also think about how to keep latency acceptable across regions and how to prevent split-brain behavior. If the interviewer wants more detail, I would describe how I would test regional failure scenarios.

I would collect logs from all services into a central pipeline with consistent formats and correlation IDs. Then I would index and store the logs in a way that supports search, filtering, and retention policies. The reason I choose this approach is that centralized logs make incident investigation much faster across many systems. I would also think about sampling, storage cost, and access control because logs can grow quickly and contain sensitive data. If the interviewer wants more detail, I would discuss how I would balance observability with cost.

I would automate repetitive and error-prone tasks such as deployments, rollbacks, health checks, and recovery workflows. The reason I choose this approach is that automation reduces manual mistakes and makes response times more consistent. I would also think about safety checks, approval gates, and rollback logic so the automation does not create new risk. If the interviewer wants more detail, I would give examples of tasks that should stay manual versus those that should be automated. In SRE work, automation should remove toil without removing judgment.

I would first restore basic visibility by adding the metrics that best reflect user impact and service health. Then I would audit the alerts, remove flaky ones, and make sure each alert has a clear owner and action. The reason I choose this approach is that good observability is the foundation of reliable on-call work. I would also think about whether the service needs new dashboards, better logging, or more tracing. If the interviewer wants more detail, I would describe how I would stage the observability improvements over time.