DevOps Engineer Interview Experience at Paytm – 2025

This coding assessment covers SQL, basic OOP, and a DSA problem, consistent with real reported Paytm assessment structures for engineering roles. The SQL section asks for a query finding the second-highest transaction amount per customer without using a hardcoded LIMIT/OFFSET approach, since that breaks with ties - a window function (DENSE_RANK) is the expected tool. The DSA question is an array-based two-pointer problem on finding pairs summing to a target value.

This round, as multiple real candidates describe, focuses on Linux commands, networking fundamentals, DBMS, and general DevOps fundamentals rather than jumping straight into cloud-native tooling. Candidates are asked to explain the difference between a hard link and a symbolic link at the filesystem level, walk through what happens during a `git rebase` versus a `git merge` and when each is appropriate, and explain database indexing tradeoffs - specifically why adding an index speeds up reads but can slow down writes, since every insert now has to update the index structure too.

The real, specifically reported focus area for this final technical round is Kubernetes, Docker, Linux, and AWS, with interviewers going deep rather than broad. On Docker, candidates are asked how the `--network` mode affects container-to-container communication and the practical difference between bridge and host networking. On Kubernetes, a common question asks how a ConfigMap change propagates to a running pod - specifically that it does not trigger an automatic restart unless the pod is set up to watch for it, which trips up many candidates who assume config changes apply instantly. The AWS portion covers IAM role assumption for EC2 instances via instance profiles rather than hardcoded credentials.