Site Reliability Engineering (SRE) plays a crucial role in blending software engineering with system administration. If you’re preparing for an SRE interview in 2025, here are the top 22 questions and answers to help you ace the process. This guide also includes SRE Practices and SRE Skills to ensure system reliability and scalability.
General SRE Interview Questions
1. What is Site Reliability Engineering (SRE)?
Answer: SRE is a discipline that applies software engineering principles to IT operations to create scalable and reliable systems. It ensures automation, monitoring, and stability of services.
2. How does SRE differ from DevOps?
Answer: While both focus on automation and collaboration, SRE emphasizes reliability by defining Service Level Objectives (SLOs) and Error Budgets, whereas DevOps focuses on CI/CD and faster deployments.
3. What are key SRE Practices and SRE Skills?
Answer:
Monitoring & Alerting
Incident Management
Capacity Planning
Error Budgets & SLOs
Automation & CI/CD
Chaos Engineering
Postmortems & Continuous Improvement
Strong problem-solving and analytical skills
Proficiency in scripting and programming languages
Deep understanding of system architecture and networking
4. Explain the Service Level Agreement (SLA), Service Level Objective (SLO), and Service Level Indicator (SLI).
Answer:
SLA: A formal contract between a service provider and customers.
SLO: A measurable goal that ensures system reliability.
SLI: Metrics that track the performance of a system (e.g., uptime, latency).
5. What is an Error Budget, and why is it important?
Answer: An Error Budget defines the acceptable downtime of a system before reliability concerns take priority over new features. It helps balance innovation with stability.
System Design & Infrastructure Questions
6. How would you design a reliable distributed system?
Answer: Use redundancy, load balancing, failover mechanisms, and database replication to ensure high availability and fault tolerance.
7. What strategies would you use for disaster recovery?
Answer:
Regular backups and testing restore processes
Failover and redundancy across multiple regions
Incident response plans and playbooks
8. How do you handle system scaling?
Answer:
Horizontal scaling (adding more servers)
Vertical scaling (upgrading resources)
Load balancing and caching
Auto-scaling based on traffic patterns
Monitoring & Incident Response Questions
9. How do you set up effective monitoring and alerting?
Answer:
Use metrics, logs, and tracing.
Define SLO-based alerting to reduce noise.
Implement dashboarding with tools like Prometheus, Grafana, and Datadog.
10. What is the difference between proactive and reactive monitoring?
Answer:
Proactive monitoring helps detect and prevent issues before they impact users.
Reactive monitoring alerts after an issue has already occurred.
11. How do you conduct an effective postmortem?
Answer:
Document the root cause, impact, and resolution.
Identify areas for improvement.
Ensure corrective actions to prevent recurrence.
12. What is a runbook, and why is it important?
Answer: A runbook is a set of step-by-step procedures for handling specific incidents, ensuring consistent and efficient troubleshooting.
Automation & CI/CD Questions
13. How does automation improve system reliability?
Answer: Automation reduces manual errors, speeds up deployments, and ensures consistency in infrastructure management.
14. What tools do you use for configuration management and automation?
Answer:
Ansible, Puppet, Chef for configuration management
Terraform for Infrastructure as Code (IaC)
Kubernetes for container orchestration
15. How would you design a CI/CD pipeline for an SRE workflow?
Answer: Use GitHub Actions, Jenkins, or GitLab CI/CD to automate:
Code build & test
Security checks
Deployment with rollback mechanisms
Monitoring and feedback loops
Security & Reliability Questions
16. How do you ensure security in an SRE role?
Answer: Implement least privilege access, encryption, patch management, and secure CI/CD pipelines.
17. What is Chaos Engineering, and why is it important?
Answer: Chaos Engineering intentionally introduces failures to test a system’s resilience and improve fault tolerance.
18. How do you prevent single points of failure (SPOFs)?
Answer:
Implement redundancy and failover strategies.
Use distributed architectures.
Regularly perform disaster recovery testing.
Behavioral & Scenario-Based Questions
19. Tell me about a time you handled a major production incident.
Answer: Follow the STAR method (Situation, Task, Action, Result), explaining how you diagnosed, resolved, and prevented the issue.
20. How do you prioritize multiple incidents at once?
Answer:
Assess impact and urgency.
Follow incident escalation policies.
Delegate tasks efficiently.
21. What would you do if an application is running slow?
Answer:
Check logs and metrics for bottlenecks.
Analyze database queries and system resource utilization.
Implement caching and load balancing.
22. How do you stay updated with SRE trends and best practices?
Answer: Follow Google SRE books, tech blogs, conferences, and SRE communities.
Final Thoughts
Mastering these SRE interview questions, understanding core SRE Practices, and improving SRE Skills will significantly improve your chances of landing a role in 2025. Stay focused on automation, system design, and incident response to succeed in an SRE career!
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