Docker is a fundamental piece of every modern application. But the set of Docker skills has changed. Back when I started teaching Docker, being good at the basics was enough. And I’m talking about building an image, spinning a container, opening a port, and pushing an image to a registry. Basics are important in 2026, but it’s also critical to understand how Docker fits into development, security, testing, and delivery workflows.
Here is my list of Docker skills every developer needs to acquire in 2026.
Basics of containers
Start learning with basic concepts: images, containers, registries, layers, ports, volumes, and networks. Understand what images and containers are and be comfortable with image building, container management, viewing logs, and cleanup of unused objects.
Why would you want to learn container fundamentals? Because you cannot properly troubleshoot the issue without the knowledge of how Docker works under the hood.
Writing a production-grade Dockerfile
A Dockerfile is the specification of how Docker should build the application’s image. Devs should be capable of creating more than just working Dockerfiles. Be familiar with the effect of image layers on the build process, Docker caching, `.dockerignore` file usage, and picking the proper base image.
And be sure to master multi-stage builds. They allow you to build your application in one stage and run it in another smaller stage, cutting the size of the final image and removing build tools and unnecessary dependencies. Efficient Dockerfiles save time, simplify deployment, and improve security.
Docker BuildKit and Buildx
Modern builds in Docker use a BuildKit backend, which improves performance and introduces useful functionality, including advanced caching and build secrets. It is important to understand how caching works to avoid rebuilding unchanged dependencies whenever the source code changes. You should learn how to use Docker Buildx if you need to build multi-architecture images, e.g., if you are developing for ARM64 but deploying on an AMD64 platform.
Docker Compose
It’s hard to find a project where there is only one application in play. In real life, you may have a web frontend, RESTful API, database, cache, and message broker all running in your application stack. Running every container manually becomes boring really quickly.
Docker Compose allows you to define all the necessary services in a YAML file, including networking, volumes, environment variables, health checks, and dependencies between services.
Also, look at Compose Watch for the ability to sync files between containers and rebuild/restart services automatically after a source code change.
Networking and storage
Networking and storage concepts will become critical for you once you go beyond single-container applications. You need to understand how services communicate with each other over the Docker network and the difference between the expose and publish configurations for ports.
Also, you should learn how volumes and bind mounts work. Containers should be replaceable, and data must not be stored inside the containers themselves. For that, you can use volumes, which allow you to store data persistently. Bind mounts are useful to share files between your laptop and the container.
These concepts will become crucial once you work with databases and multi-container applications.
Container security
Security is no longer something that you add when it’s time to ship an app. Container security is shaped by the choice of base image, installed dependencies, permissions, and secrets management. You should learn how to avoid running your application as root if possible, update your dependencies, use small and verified base images, and never include passwords and API keys in your images. You should also know how to perform vulnerability scanning of your images. Docker Scout can help you detect potential vulnerabilities and analyze image contents.
Docker in CI/CD
Running containers locally is just a part of the Docker workflow. However, you should be aware of the flow of images in a CI/CD pipeline. The typical CI/CD flow might be something like: build an image, run automated tests, perform vulnerability scanning, tag the image, push the image to the container registry, and deploy it to some other environment.
You don’t need to become a DevOps specialist, but understanding the flow of your app from source code to container image to the deployed application is going to make you a more valuable developer in modern teams.
Develop troubleshooting skills
One of the most valuable Docker skills is how to troubleshoot a failing container. Try to practice log analysis, poking into containers, looking at environment variables, testing network connectivity, inspecting health checks, and running commands inside the container.
Think about such questions as: Has the container started successfully? Did the application crash? Is the correct port exposed? Can containers communicate? Are volumes mounted correctly?
Developing troubleshooting skills makes your knowledge of Docker more practical.
Ready to Build Your Docker Skills?
If you want to put these Docker fundamentals into practice, check out my Docker: Your First Project course on LinkedIn Learning. The course walks you through building and running your first Dockerized application and is part of the Docker Foundations Professional Certificate Learning Path.