TCS DevOps Engineer Interview Questions

"Continuous Integration (CI) automatically builds and tests code updates every time a developer merges changes. Continuous Delivery extends this by staging the built release package so it is ready for deployment at the click of a button. Continuous Deployment automates the entire pipeline, pushing every validated build directly to production with zero manual intervention."

"To design a secure pipeline, I ensure secrets are stored in a secure vault (like HashiCorp Vault) rather than hardcoded. I run static code analysis (SAST) and dependency scanner tools during the build step. Container images are scanned for vulnerabilities before registry push. The final deploy step uses IAM service accounts with least-privilege permissions, and rolling updates verify server health before traffic routing."

"Infrastructure as Code involves provisioning and managing systems using configuration files instead of manual console clicks. Using Terraform offers major benefits: it uses a declarative language to define our desired state, maintains a state file to track resources, detects configuration drift, and allows us to duplicate environments (like staging and production) reliably."

"When a microservice went down and blocked checkout flows (Situation), I had to restore services immediately (Task). I checked our Prometheus alerts, found database connection pools were exhausted, and identified a lock on the users table (Action). I terminated the blocked query, restarted the service instances, and set query timeouts to prevent similar locks (Result), restoring checkout service within 10 minutes."

"Virtual Machines virtualize physical hardware, with each VM running its own full guest OS via a hypervisor. Docker containers virtualize the operating system, sharing the host OS kernel and running as isolated user-space processes. Containers communicate using Docker networks, such as overlay networks in cluster environments or bridge networks on single hosts."

"GitOps is a practice where Git repositories serve as the single source of truth for our infrastructure state. We define our desired state in Git, and an agent (like ArgoCD) continuously reconciles it with the active cluster state. This improves safety by providing automated audit logs, preventing manual cluster overrides, and allowing instant rollbacks by reverting Git commits."