DevOps Engineer Interview Experience at Groww – 2025

Covers Linux fundamentals, basic networking, and a coding problem asking candidates to implement a simple in-memory pub-sub mechanism, simulating how real-time market data might fan out to many subscribed clients efficiently rather than iterating over every subscriber for every update.

Focused specifically on infrastructure for maintaining a large number of concurrent WebSocket connections delivering live market data. Candidates are asked how a load balancer needs to be configured differently for WebSocket traffic compared to standard HTTP request-response traffic - specifically that connections are long-lived and stateful, so the load balancer needs sticky sessions or a connection-aware routing strategy, since a client reconnecting to a different backend node mid-session would lose its subscription state. Interviewers also ask how to handle a rolling deployment without dropping all active WebSocket connections at once; draining connections gradually from nodes being replaced is preferable to an abrupt cutover.

Covers monitoring design specifically for connection-heavy infrastructure - tracking active WebSocket connection counts per node, reconnection rates as a leading indicator of instability, and message delivery latency percentiles rather than just server-side request latency, since the actual user-facing metric that matters is how fresh the market data is by the time it reaches the client.

A culture-fit conversation covering comfort with a fast-moving product environment and how a candidate would prioritize infrastructure reliability work against feature-driven pressure from product teams.