CI/CD: The Essential Minimum for Every Developer
As you progress in your career as a developer, the business starts expecting skills typical of a T-shaped professional (). This means it’s no longer enough to just write clean and efficient code. You also need to have at least a basic understanding of how code gets delivered to production.
Surprisingly, even experienced senior developers can find themselves unprepared to answer questions about CI/CD. Let’s break it down and explore what a basic CI/CD pipeline should look like.
CI: Continuous Integration
Continuous Integration (CI) refers to the process of integrating code changes continuously and safely. Let’s address this definition:
1. Changes
Modern software development is unimaginable without version control systems (VCS). They allow us to track and manage code changes effectively, making VCS the foundation of CI.
Hard to believe, but I’ve encountered companies that still don’t use a version control system in 2025. 😳
2. Continuous Integration
With a VCS, all changes are visible and can be merged into the main branch as needed. But how often should this happen? Can it still be called “continuous integration” if changes are merged only once a day, say, overnight?
The less frequently changes are integrated, the greater the risk of merge conflicts, which often need to be resolved manually. This increases the likelihood of errors. To avoid this, changes should be merged as frequently as possible.
Long-lived feature branches can cause problems: they lag behind the main branch, requiring regular merges to stay up-to-date. One solution is adopting the approach, which demands a certain level of team maturity.
3. Safe Integration
Merging changes frequently isn’t enough. How do you ensure that these changes don’t break anything? The answer: tests, tests, and more tests.
Tests, particularly unit tests, should be part of the CI pipeline and executed with every push. Unit tests are fast and efficient, making them ideal for early feedback.
Additionally, linting tools can enforce coding standards and serve as a quality gate, helping maintain high-quality code.
A well-configured CI pipeline ensures that your code is always ready for deployment.
CD: Continuous Delivery
Continuous Delivery (CD) transforms your code into an artifact ready for deployment.
1. Building the Artifact
The process starts with building the artifact in a safe and reproducible environment. Reproducibility is crucial here; external factors like third-party software or configuration differences can compromise build quality.
For this reason, building on a developer’s local machine is not ideal. A better solution is using containers. Containers provide a consistent environment for every build and can be discarded after the build process is complete.
2. Versioning
Every artifact must have a version. Without versioning, it’s easy to deploy incompatible changes or roll back to the wrong version. Versioning ensures traceability and confidence in the deployment process.
Continuous Deployment: Automated Delivery to Production
Continuous Deployment is often confused with Continuous Delivery, but they are not the same. Continuous Deployment is a subset of Continuous Delivery and involves automatically deploying the artifact to production.
This practice enables teams to achieve elite , such as deployment frequency and lead time for changes. However, it requires a high level of development and operational maturity.
Conclusion
CI/CD is a set of practices that help teams deliver faster and more reliably. The higher your level as a developer, the more responsibility you have to understand and implement these practices effectively.
