Dev Ops Interview Questions

What is CI/CD?

CI/CD stands for Continuous Integration and Continuous Delivery/Deployment — a practice where developers merge code frequently into a shared branch (CI), trigg…

Containers vs Virtual Machines

Containers and virtual machines both isolate applications, but a container shares the host operating system’s kernel and packages only the app plus its depende…

What is Kubernetes?

Kubernetes is an open-source container orchestration platform that automates deploying, scaling, and managing containerized applications across a cluster of ma…

What is Infrastructure as Code?

Infrastructure as Code (IaC) is the practice of provisioning and managing infrastructure — servers, networks, databases, and more — through machine-readable de…

What is Docker?

Docker is a platform that packages an application together with its dependencies, libraries, and runtime into a lightweight, portable unit called a container,…

What is a Docker Image vs a Container?

A Docker image is a read-only, layered blueprint containing the application code, dependencies, and configuration, while a container is a running, writable ins…

What is a Dockerfile?

A Dockerfile is a plain-text script of sequential instructions that tells the Docker engine exactly how to assemble a Docker image, layer by layer.

Blue-Green vs Canary Deployment

Blue-green deployment runs two full, identical production environments and switches all traffic from the old (blue) to the new (green) version at once, while c…

What is a Kubernetes Pod?

A Kubernetes Pod is the smallest deployable unit in Kubernetes — a group of one or more tightly coupled containers that share the same network namespace, IP ad…

What is a CI/CD Pipeline?

A CI/CD pipeline is the automated sequence of stages — checkout, build, test, and deploy — that takes a code change from commit to running in an environment, w…

What is GitOps?

GitOps is an operational practice where a Git repository is the single source of truth for declarative infrastructure and application configuration, and an aut…

What is a Helm Chart?

A Helm chart is a packaged, versioned bundle of Kubernetes manifest templates plus a values file that lets you configure and install a complete application ont…

What is a Service Mesh?

A service mesh is an infrastructure layer that handles service-to-service communication for you by injecting a lightweight proxy alongside every service instan…

What is Log Aggregation?

Log aggregation is the practice of collecting log output from many distributed services, containers, and hosts into one centralized system where it can be sear…

How Do Docker Image Layers and Build Caching Work?

Each instruction in a Dockerfile produces an immutable, content-addressed image layer, and Docker’s build cache reuses a previously built layer whenever the in…

What is a Docker Multi-Stage Build?

A multi-stage Docker build uses multiple FROM instructions in one Dockerfile, where each stage can compile or prepare artifacts and only the final stage copies…

How Do Docker Volumes Persist Data?

Docker volumes are storage areas managed by the Docker engine, living outside any single container’s writable layer, so data written to a volume survives conta…

How Does Docker Networking Work?

Docker networking connects containers using virtual network drivers — most commonly the bridge driver, which creates an isolated virtual network on the host wh…

What is Docker Compose and When Do You Use It?

Docker Compose is a tool for defining and running multi-container applications from a single declarative YAML file, letting you start, stop, and network an ent…

What Are Dockerfile Best Practices?

Dockerfile best practices center on minimizing image size and build time while maximizing cache reuse and security: use a small pinned base image, order instru…

What is a Docker Registry?

A Docker registry is a storage and distribution service for container images, organized into repositories and tags, that lets teams push built images and pull…

What is a Container Runtime?

A container runtime is the low-level software component that actually creates, starts, and manages the lifecycle of a container on a host by configuring Linux…

Docker vs Podman: What Is the Difference?

Docker relies on a persistent background daemon (dockerd) running as root to build and manage containers, while Podman is daemonless — each podman command dire…

What Are Distroless Images?

Distroless images are minimal container base images that contain only an application and its direct runtime dependencies — no shell, package manager, or OS uti…