Chroma India Site Reliability Engineer Interview: Rounds, Questions and Preparation

What the job involves

Site Reliability Engineers (SREs) at global tech companies ensure that large-scale distributed systems are reliable, scalable, and efficient. They combine software engineering and systems engineering to build automation, monitor services, and respond to incidents. Day to day, an SRE might write code to improve reliability, analyze system metrics, or participate in on-call rotations to troubleshoot production issues.

Role and Technical Knowledge

1. 1

   What is the difference between a Site Reliability Engineer and a DevOps Engineer?

   Highlight that SRE focuses on reliability through software engineering, while DevOps emphasizes collaboration and automation across the lifecycle. Mention SRE's use of error budgets and SLIs/SLOs.

2. 2

   Explain the concept of an error budget and how it influences release cycles.

   Define error budget as the acceptable amount of downtime or failure. Explain that if the budget is exhausted, releases may be paused to focus on reliability.

3. 3

   How would you monitor a web application's health? What metrics would you track?

   Mention the four golden signals: latency, traffic, errors, and saturation. Also include uptime, request rate, and resource utilization.

4. 4

   What is the role of automation in SRE? Give an example.

   Discuss automating repetitive tasks like deployments, scaling, and incident response. Example: auto-scaling based on CPU usage or automated rollbacks.

Practical Scenarios

1. 5

   You receive an alert that a service's latency has spiked. How do you troubleshoot?

   Outline a systematic approach: check recent changes, examine metrics (CPU, memory, network), review logs, and use tracing. Prioritize restoring service first.

2. 6

   Describe how you would design a highly available system for a global user base.

   Cover multi-region deployment, load balancing, data replication, and failover strategies. Mention trade-offs between consistency and availability.

3. 7

   A deployment causes errors in production. What steps do you take?

   Immediate rollback, then analyze logs and metrics to identify the cause. Implement a fix and add safeguards like canary deployments.

4. 8

   How would you handle a sudden increase in traffic to your application?

   Discuss auto-scaling, caching, CDN usage, and rate limiting. Also mention capacity planning and load testing.

Behavioural and HR

1. 9

   Tell me about a time you faced a technical challenge and how you overcame it.

   Use the STAR method. Focus on your problem-solving process, teamwork, and the outcome.

2. 10

   How do you prioritize tasks when multiple incidents occur simultaneously?

   Emphasize assessing impact and urgency. Mention communication with stakeholders and delegating when possible.

3. 11

   Why do you want to work as an SRE, especially in a fast-growing company?

   Show passion for reliability and automation. Connect to the company's scale and your desire to learn in a dynamic environment.

4. 12

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

   Highlight your learning approach, resources used, and how you applied it effectively. Show adaptability.

Coding and Systems

1. 13

   Write a Python script to check if a service is reachable and log the result.

   Use requests or socket module. Include error handling and logging with timestamps.

2. 14

   Explain how you would use a configuration management tool like Ansible in an SRE context.

   Discuss automating server configuration, ensuring consistency, and integrating with CI/CD pipelines.

3. 15

   What are some best practices for writing a Dockerfile for a production service?

   Use minimal base images, multi-stage builds, non-root user, and avoid unnecessary packages. Mention layer caching.

4. 16

   How does Kubernetes help in achieving reliability?

   Cover self-healing, rolling updates, auto-scaling, and service discovery. Mention liveness and readiness probes.