Netflix DevOps / SRE Interview Questions

1.Tell me about a time you solved a reliability issue by giving your team more ownership instead of adding more processes or controls.

2.Describe a monitoring or alerting problem you solved by trusting your team's expertise rather than implementing standard procedures.

3.Describe a time you made a significant infrastructure decision without getting explicit approval. What was the decision and how did you ensure accountability?

4.Tell me about a time you provided context to your team that helped them make better decisions about an incident response or architectural choice.

5.Walk me through a time you had to help an underperforming teammate improve or transition off your team. How did you handle it?

6.Walk me through the biggest technical risk you took in the last two years. What was at stake and how did you manage the accountability?

7.Netflix's streaming traffic spikes 40% during a major show release and your Kubernetes cluster starts throttling pods. How would you quickly scale the infrastructure to handle this load?

8.You're deploying a new microservice using Spinnaker to production, but the canary deployment shows a 2% increase in error rate. The product team is pressuring you to proceed because it's a high-priority feature. What's your approach?

9.Our recommendation engine's Kafka cluster is showing increased latency during peak hours, affecting real-time personalization. Walk me through how you'd diagnose and fix this performance issue.

10.You need to implement chaos engineering for Netflix's CDN edge servers to test resilience during regional failures. How would you design and safely execute these experiments?

11.Netflix's ads platform needs to process bid requests with sub-10ms latency while maintaining 99.99% availability. Design the infrastructure architecture to meet these requirements.

12.You discover that Netflix's content encoding pipeline on Titus is failing for 5% of uploads, but only for videos over 2GB. The failure pattern started after a recent Kubernetes upgrade. How do you investigate and resolve this?

13.Design a monitoring system that can track the health of Netflix's 15,000+ microservices in real-time. How would you ensure the monitoring itself doesn't become a bottleneck?

14.Design a chaos engineering platform for Netflix's recommendation engine infrastructure that can safely test failure scenarios without impacting the personalized experience for millions of users.

15.Netflix's Open Connect CDN needs to automatically decide which content to pre-position at edge locations before users request it. Design the system that makes these caching decisions across thousands of edge servers globally.

16.Design the infrastructure for Netflix's A/B testing platform that needs to consistently assign users to experiments across all Netflix services while maintaining user privacy and test integrity.

17.Netflix Games needs a leaderboard system that can handle millions of concurrent players across hundreds of games while preventing cheating and maintaining real-time updates. How would you architect this?

18.Design the deployment system for Netflix Studio Technology's rendering pipeline that processes thousands of high-resolution video files daily. The system must handle both scheduled batch jobs and urgent priority renders without affecting ongoing work.

19.Describe a time you had to make a judgment call about system reliability without having all the information you wanted. How did you decide and what was the outcome?

20.Describe a time you shared information that wasn't strictly necessary to share but helped Netflix as a whole. What prompted you to do it and what happened?

21.Tell me about a time you convinced a team outside your organization to change how they operated for the benefit of Netflix's overall reliability or performance.

22.Walk me through a time you learned something completely outside your expertise that ended up helping you solve a Netflix problem better. What drove you to explore that area?

23.Tell me about the most significant infrastructure change you drove that others initially thought was risky or unnecessary. How did you build support for it?

24.Tell me about a time you had to communicate bad news about system performance or reliability to stakeholders who were counting on you. How did you handle that conversation?

25.Estimate how much bandwidth Netflix would save globally if we reduced the bitrate of our standard definition streams by 10%. Walk me through your calculations and key assumptions.

26.A major ISP is throttling Netflix traffic during peak hours, affecting 15% of our US subscribers. Estimate the potential subscriber churn impact and propose both technical and business approaches to address this.

27.Netflix's recommendation API response times increased by 15ms globally last week, but no code shipped and infrastructure metrics look normal. How would you systematically investigate this performance degradation?

28.Estimate the compute cost impact if Netflix's encoding pipeline had to re-encode 20% of our catalog to support a new device format. What would be your approach to minimizing this cost?

29.You notice that Netflix's mobile app crash rate increased from 0.1% to 0.3% over the past month, but only in specific geographic regions. Walk me through how you'd investigate and resolve this issue.

30.Netflix wants to launch a live sports streaming feature. Estimate the additional CDN capacity we'd need to support 50 million concurrent viewers for a major event, and how this differs from our current on-demand infrastructure.