Stripe Site Reliability Engineer Interview: Rounds, Questions and Preparation

What the job involves

Site Reliability Engineers (SREs) keep large-scale production systems fast, available, and reliable. In global tech companies, they split their time between writing automation and tooling, responding to incidents, and improving system design to prevent repeat failures. Freshers usually start by owning small services, building observability, and participating in on-call rotations with mentorship.

Role and technical knowledge

1. 1

   What does an SRE do differently from a traditional software engineer?

   Mention shared ownership of production, SLOs and error budgets, automation over manual toil, and incident response. Show you understand reliability as an engineering problem.

2. 2

   Explain SLI, SLO, and SLA with a simple example.

   Define each clearly: SLI is a measured signal (e.g., request latency), SLO is an internal target, SLA is a contract with consequences. Use a concrete service like a payments API.

3. 3

   How would you monitor a web service to know it is healthy?

   Cover the four golden signals (latency, traffic, errors, saturation), plus logs, traces, and synthetic checks. Mention dashboards and alerting thresholds.

4. 4

   What happens during an incident, and what is a postmortem?

   Describe detection, triage, mitigation, and communication. A postmortem is a blame-free document that finds root causes and action items to prevent recurrence.

Practical scenarios and troubleshooting

1. 5

   Users report that a checkout page is slow in one region. How do you debug it?

   Start with dashboards and recent changes, check latency by region, inspect DNS, CDN, and backend dependencies. Propose a hypothesis, test it, and mitigate before deep root cause.

2. 6

   A service is returning 500 errors after a deploy. What do you do first?

   Check deploy logs and error rates, consider rolling back if impact is high, and verify whether the issue is code, config, or dependency. Communicate status to stakeholders.

3. 7

   How would you reduce toil in a team that manually restarts a service every night?

   Identify the root cause, then automate with a health check and restart script or a Kubernetes liveness probe. Add monitoring to confirm the fix and prevent silent failures.

4. 8

   You get an alert at 2 AM about high CPU on a database. Walk through your steps.

   Acknowledge the alert, check dashboards and recent changes, look for slow queries or traffic spikes, and apply a safe mitigation. Escalate if needed and document the timeline.

System design and reliability engineering

1. 9

   Design a simple URL shortener that can handle millions of requests per day.

   Cover load balancing, stateless app servers, a database or key-value store, caching, and how you would monitor latency and error rates. Mention capacity estimates.

2. 10

   How would you make a service resilient to a single data center failure?

   Discuss multi-region or multi-zone deployment, health checks, failover, data replication, and testing with game days. Mention trade-offs like cost and consistency.

3. 11

   What is an error budget, and how does it change team behaviour?

   Explain that it is 1 minus the SLO, and it balances feature velocity with reliability work. If the budget is exhausted, teams prioritize reliability fixes.

4. 12

   How do you safely roll out a new version of a service?

   Mention canary releases, blue-green deployments, feature flags, automated rollback, and monitoring key metrics during and after the rollout.

Behavioural and HR questions

1. 13

   Tell me about a time you fixed a problem under time pressure.

   Use the STAR method. Focus on how you stayed calm, prioritized impact, communicated, and what you learned. Avoid blaming others.

2. 14

   Describe a situation where you had to learn a new technology quickly.

   Show curiosity and structure: how you found resources, built a small project, and applied it. Connect it to reliability or automation if possible.

3. 15

   How do you handle disagreement with a teammate about a technical decision?

   Emphasize listening, using data and SLOs to decide, and committing to the team decision even if you disagreed. Mention blameless communication.

4. 16

   Why do you want to work as an SRE, and why at a company like ours?

   Link your interest in automation, scale, and production ownership to the company's products and engineering culture. Be specific about what you want to learn.