TikTok SRE Interview Experience — One-Hour Technical Screen Covering K8s, SLOs, and LeetCode 94

Interview process

• Overall it was a technical interview lasting about 1 hour
• The interviewer was pretty friendly, but the questions covered a wide range — felt like they were testing general SRE skills plus coding fundamentals

Interview content

1. Kubernetes
   • Asked some basic K8s principles, like the difference between Pod and Deployment, and what a Service does.
   • Also asked how to debug a Pod that fails to start.
2. Python trivia
   • Asked common Python questions, like mutable vs immutable objects, shallow copy vs deep copy, what the GIL does, etc.
3. SLO (Service Level Objective)
   • Had me explain the difference between SLO, SLA, and SLI.
   • Asked what to do if the actual error rate exceeds the SLO.
4. Distributed System Troubleshooting
   • Gave a scenario where request latency in a distributed system was very high, and asked which areas to investigate.
   • Things like network, load balancer, DB, cache, the service itself, etc.
5. NoSQL vs SQL
   • Asked about the difference between NoSQL and SQL, and when to choose NoSQL.
   • I answered with schema flexibility, horizontal scalability, and suitability for high-concurrency/massive-data scenarios.
6. LeetCode Coding
   • Tested LeetCode #94: Binary Tree Inorder Traversal.
   • I wrote both the iterative and recursive solutions.

Overall impressions

• TikTok's SRE interview leans more toward a Dev + Ops combination — you need coding ability, but you also need to understand distributed systems and ops principles.
• I feel like if you're interviewing for SWE instead, it's probably more algorithm- and system-design-heavy.
• My advice for anyone preparing: review K8s basics, Python trivia, core SRE concepts (SLO/SLI/SLA), distributed troubleshooting approaches, and grind some basic LeetCode binary tree/linked list problems.