Devops
294 bites tagged Devops — interview questions with model answers, and 60-second explainers.
Managing secrets for containerized Node.js on Kubernetes
Use Kubernetes Secrets or an external vault, mount as files not env, encrypt at rest, rotate. secure secret handling in orchestration. baking credentials into images or trusting plain env vars as secure.
How do SRE and DevOps relate?
DevOps is a broad culture of breaking down silos; SRE is one prescriptive way to do it with specific practices. whether you see SRE as a concrete implementation of DevOps principles, not a rival.
Strategy for large multi-team IaC projects
Versioned reusable modules, state split per environment and component, promotion of identical code via variables, and externalized secrets. scaling IaC organizationally. one giant shared state or secrets in code.
State drift in Terraform
Drift is when live infrastructure diverges from recorded state, usually via manual console changes; detect with plan or refresh, remediate by re-applying or importing. IaC state versus reality. hand-editing state.
What is Infrastructure as Code?
IaC defines infra in version-controlled files, giving repeatability, peer review, and drift-free consistency, unlike error-prone console clicks. the case for declarative infrastructure. calling it mere scripting.
Docker Compose profiles for optional services
Profiles tag services so they stay off by default, activate via --profile or COMPOSE_PROFILES, and unprofiled services always run. gating optional services in one Compose file.
Structuring Compose files across environments
A base compose.yaml plus override files, the default override auto-merge, and explicit -f flags or extends per environment. Compose override and merge mechanics.
What is a build artifact? Give Java, JS, and C++ examples.
Define artifacts as compiled outputs; list JAR/WAR for Java, webpack bundle for JS, and binary/.so for C++; note immutability. Your grasp of the source-to-deployable boundary in CI/CD.
How do you speed up slow integration tests without compromising quality?
Tests your ability to optimize CI/CD pipelines while preserving coverage. A strong answer covers parallel execution, Test Impact Analysis, ephemeral containers, and test data as code. Red flag: proposing to delete tests or disable integration stage entirely.
Compare Terraform and Ansible: when to use each and both together
This tests whether you distinguish provisioning from config management. Strong answers define Terraform for immutable infra and Ansible for mutable state, contrast day 0 versus day 1-2 work, and cover Terraform for VMs and Ansible for setup.
What is IaC and its CI/CD benefits over manual provisioning?
Cover descriptive models, idempotency, and on-demand environments for repeatable CI/CD. Your understanding of IaC as versioned, declarative infrastructure that stops snowflake environments and drift.
How would you integrate artifact signing into CI/CD and secure the keys?
Tests supply chain architecture and secrets management. A strong answer: remote HSM or KMS signing isolated from build runners, signature verification at deploy gates, and key rotation with audit logging.
What is Infrastructure as Code (IaC), and how does it support CI/CD?
This tests if you link declarative definitions to repeatable pipelines. A strong answer covers idempotence, versioned templates, and preventing snowflake environments. A red flag is calling IaC mere scripting without CI/CD integration.
What does shift left mean in CI/CD, and give two concrete examples?
Your grasp of moving verification earlier to reduce cost and risk. Define shift left as earlier-stage testing; cite two concrete examples like pre-commit unit tests and PR-level SAST scans. Never call it "more testing" instead of earlier feedback.
Continuous Delivery vs Continuous Deployment: key differences and choosing between them
Tests the human-gate distinction: Delivery readies artifacts but requires manual approval; Deployment pushes automatically. Strong answers cite compliance, blast radius, and maturity. Red flag: conflating terms or claiming full automation fits every app.
Explain multi-stage Docker builds for Python and builder vs runtime
Tests separation of build-time and runtime concerns. A strong answer contrasts the builder stage (gcc, headers, wheels) with the runtime stage (slim base, copied artifacts, no compiler). Red flag: citing size alone while ignoring security and caching.
Walk me through a basic Dockerfile for a FastAPI app
Slim base, install deps before app code to cache layers, expose port, exec-form CMD for Uvicorn. Docker layering and build cache for Python containers. Shell-form CMD or code-before-requirements, killing cache.
Docker Compose for Local FastAPI Stacks
Docker Compose turns your laptop into a one-command datacenter. Define Postgres, Redis, and your FastAPI app in one YAML file and they boot as a networked stack.
FastAPI Container Build and Deploy Pipeline
Treat the Docker image as the immutable artifact: one build runs everywhere. Deploy FastAPI workers behind a load balancer, one process per container. The footgun is baking secrets into the image or running multiple processes; that breaks horizontal scaling.
DevOps Is Culture, SRE Is Engineering
DevOps is a cultural philosophy for fast, safe delivery; SRE is the engineering discipline that implements it with error budgets and SLOs. They are complementary, not rival job titles. The footgun is hiring SREs and declaring DevOps done.
How do you version and distribute Docker dev environments consistently?
Tests immutable dev environment distribution. Strong answers cover: versioned Dockerfiles in Git, immutable image tags pushed to a registry, and enforcing identical pulls for CI and developers. Red flag: using the "latest" tag or local Dockerfile rebuilds.
How do you build dev and production Docker images from one source?
Mastery of Docker multi-stage builds for isolating dev and production dependencies. Use a base stage, a dev target with linters and tests, and a lean production target copying only the build artifact. Separate Dockerfiles or dev tools in production.
What are the primary differences between traditional DevOps and MLOps?
Tests if you know MLOps extends CI/CD to data and probabilistic assets. Contrast code artifacts with models and datasets. Distinguish commit triggers from drift or retraining triggers. Red flag: treating models as static binaries and ignoring data lineage.
Walk me through a Flutter CI/CD pipeline for Play Store and TestFlight
Tests your ability to orchestrate multi-platform Flutter builds, manage signing secrets, and automate deployments to Google Play Internal Testing and Apple TestFlight.
Get Devops bites daily.
Five a day, five minutes, offline. With quizzes so it sticks.
Open testing — you’ll join as an early tester.