Microsoft Site Reliability Engineer Interview Questions

I would start by modeling the bottlenecks in CPU, memory, storage, network, and external dependencies. Then I would estimate the headroom needed and define where autoscaling or capacity expansion is required. The reason I choose this approach is that capacity planning should be based on the actual constraint, not just a rough guess. I would also think about failover capacity and whether the system can survive a partial region loss at that scale. If the interviewer wants more detail, I would explain how I would review the plan regularly as traffic changes.

I would roll out patches gradually with health checks, canaries, and clear rollback paths. Then I would monitor service health, error rates, and capacity after each wave so I can stop if the patch introduces risk. The reason I choose this approach is that large-scale patching should minimize blast radius and preserve user availability. I would also think about maintenance windows, automation, and how to handle a failed patch on a subset of machines. If the interviewer wants more detail, I would describe how I would coordinate with service owners.

I would start with the highest-value signals: request success rate, latency, and saturation, then add structured logs and traces around key flows. The reason I choose this order is that basic visibility usually solves the majority of incident triage problems first. I would also think about dashboard ownership, log retention, and whether the signals are tied to user-facing symptoms. If the interviewer wants more detail, I would explain how I would prioritize the work over the first 30 to 60 days. The goal is to move from blind spots to actionable visibility as quickly as possible.

I would include runbooks, dashboards, log search, deployment history, incident timelines, and safe remediation scripts. The reason I choose these features is that on-call engineers need to go from alert to diagnosis to action as quickly as possible. I would also think about access control, auditability, and making the tools easy to use under stress. If the interviewer wants more detail, I would explain how I would keep the toolbox updated as services change. A good toolbox should reduce guesswork during incidents.

I would look at the current SLO performance and the remaining error budget before deciding how much release risk the service can take. If the error budget is healthy, the team can move faster on features; if it is low, reliability work should take priority. The reason I choose this framework is that it makes the trade-off explicit instead of turning it into a subjective argument. I would also think about trend direction, not just the current number, because a service that is getting worse needs earlier intervention. If the interviewer wants more detail, I would explain how I would communicate the decision to stakeholders.