Before Docker, deploying a Node.js application meant installing Node, npm, and every dependency on the server — and hoping the versions matched what the developer used. Docker packages the application and everything it needs into a single portable unit. Engineers at Swiggy, Razorpay, and CRED run thousands of containers in production every day, and this pillar starts from the beginning: what a container actually is and how to work with it.
What This Pillar Covers
- Understanding containers vs virtual machines — what makes containers lightweight and fast
- Running, stopping, inspecting, and debugging Docker containers with docker run and docker exec
- Building Docker images with Dockerfiles — FROM, RUN, COPY, CMD, ENTRYPOINT, and layer caching
- Managing the container lifecycle — start, stop, restart, remove, and log inspection
Who This Is For
Developers and DevOps engineers who are new to Docker or want to solidify their understanding of how containers work before moving to Kubernetes and production orchestration.
Why This Matters in Production
At CRED and Razorpay, every microservice runs inside a container. A developer who cannot build, debug, or inspect containers cannot contribute effectively to the deployment pipeline or diagnose production issues.
Prerequisites
- Basic Linux command line (cd, ls, cat, chmod)
- Familiarity with how applications are deployed on a server
- Understanding of what an IP address and a port number are