DevOps Engineer Interview Questions
372 questions across 38 categories
The bulk of a working DevOps engineer's day-to-day: hands-on tooling, common troubleshooting, and the practical judgment calls that come up once you're actually operating systems.
Under a traffic spike, your application starts throwing 'too many connections' errors from the database, even though the database itself isn't under heavy CPU or memory load. What's happening?
IntermediateDatabases7 min
Can a small startup meaningfully practice SRE, or does the error-budget/SLO machinery only make sense past a certain scale?
BeginnerSRE6 min
A job posting says the team practices 'continuous deployment,' but during the interview it turns out every release still requires a manual approval click. Is that actually continuous deployment?
BeginnerDevops5 min
Your company's microservices architecture has oddly chatty, tightly-coupled services that mirror exactly how your engineering org is divided into teams. Is that a coincidence?
IntermediateDevops6 min
A team's definition of 'done' for infrastructure changes is just 'terraform apply succeeded.' What's actually missing from that definition, and why does it matter?
IntermediateDevops6 min
Terraform and Ansible can both technically install packages on a server. What's the actual conceptual difference between infrastructure-as-code and configuration management?
BeginnerDevops6 min
A team is proud that their service hasn't had a major incident in 8 months, but when something does break, it takes hours to recover. Which reliability metric should they actually be optimizing for?
IntermediateDevops6 min
Leadership wants to 'shift left' on security, testing, and cost — but the phrase is used so broadly it's started to feel meaningless. What does shift-left actually mean, concretely?
BeginnerDevops6 min
What's actually the difference between DevOps, SRE, and Platform Engineering — as practices, not just job titles — and how would you explain it to someone outside the team?
BeginnerDevops6 min
What's the actual difference between idempotency and "safe to re-run" — can a task be safely re-run without actually being idempotent?
IntermediateDevops6 min
How would you tell whether a company's "Platform Engineering" team is genuinely building self-service tooling, versus just being the old ops team under a new name?
IntermediatePlatform Engineering6 min
Joining a company with none of DevOps, SRE, or Platform Engineering formalized, which would you introduce first, and why?
IntermediateDevops7 min
What's the trade-off between running security scans as a separate CI job versus as a local pre-commit/pre-push hook?
IntermediateDevSecOps6 min
How would you measure whether engineers are actually acting on security scan findings, versus just dismissing them to unblock their PR?
IntermediateDevSecOps6 min
How would you handle a pre-existing backlog of medium-severity security findings that predates your new scanning rollout, without blocking every team's work on day one?
IntermediateDevSecOps7 min
How would you integrate SAST, dependency scanning, and secrets scanning into a CI/CD pipeline without making every single PR painfully slow?
IntermediateDevSecOps8 min
Your container scanner reports 200+ vulnerabilities in a base image you didn't choose and can't easily replace. How do you triage this into something actionable?
IntermediateDevSecOpsDocker7 min
What's the actual trade-off between pinning exact dependency versions and allowing floating version ranges, from a supply-chain security perspective?
IntermediateDevSecOps6 min
What's the actual difference between a Docker image and a Docker container? People use the words interchangeably, but they're not the same thing.
BeginnerDocker5 min
What's the tradeoff between alpine and slim/distroless base images for a Node.js service?
IntermediateDockerNodejs6 min
How does Docker layer caching behave differently on CI runners without a persistent Docker daemon between builds, and how would you mitigate the resulting slowdown?
IntermediateDocker6 min
Your CI pipeline's Docker build takes 12 minutes and produces a 1.8GB image for a small Node.js service. How would you diagnose and fix it?
IntermediateDockerNodejsCI/CD10 min
What's the difference between a container's internal port and a host-published port, and how does confusing them cause debugging headaches?
BeginnerDocker5 min
How does Docker's DNS-based service discovery actually work under the hood for containers on a user-defined network?
IntermediateDocker6 min