Site Reliability Engineering roles have exploded, and in 2026 companies want engineers who understand reliability as a feature — not just someone who can run kubectl. This guide collects the 50 most common SRE interview questions asked at companies from hypergrowth startups to FAANG, with answers grounded in real production practice.
The questions span six domains: SRE fundamentals (SLI/SLO/SLA, error budgets, toil), operations and culture (incident management, blameless postmortems, chaos engineering), observability (Prometheus, Grafana, OpenTelemetry, AI-powered monitoring), Kubernetes reliability (PodDisruptionBudgets, topology spread, HPA/VPA, RBAC security), automation and IaC (Terraform, GitOps, canary vs blue-green deployments), and system design with reliability constraints. Every answer reflects what hiring managers actually ask in 2026 — not textbook definitions.
Sample: "What is an error budget and how is it used?" Answer: The amount of allowed unreliability before users become unhappy. If your SLO is 99.9%, your error budget is 43 minutes of downtime per month. When the budget is healthy, ship faster. When it's burned, freeze all feature launches and focus on reliability. This single number replaces endless debates between product and SRE. Another: "Compare canary vs blue-green deployments." Answer: Blue-green shifts 100% traffic instantly after validation (fast rollback, double infrastructure). Canary shifts gradually (5% → 25% → 100%) monitoring at each step — slower but catches problems before they affect all users. Many teams combine both: canary to validate, blue-green cutover once proven stable.
Whether you're preparing for your first SRE role or leveling up to Senior, these 50 questions cover the depth and breadth that separates candidates who get offers from those who don't.
All 50 questions broken down by level — junior, mid, senior, staff — with detailed answers and insider tips on what hiring managers are actually looking for. Full guide at devtocash.com
Originally published at devtocash.com
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