What is CI/CD

CI/CD stands for Continuous Integration and Continuous Deployment (or Delivery).

• Continuous Integration (CI):
  • Developers frequently merge (integrate) their code changes into a shared repository (like GitHub, GitLab, or Azure Repos).
  • Every time code is pushed, automated builds and tests run to ensure nothing is broken.
  • Goal: Catch bugs early, keep the codebase stable, and reduce integration issues.
• Continuous Delivery (CD - Delivery):
  • After CI, the code is packaged and automatically made ready for release to production.
  • Deployment to production is still a manual approval step (to control when to release).
• Continuous Deployment (CD - Deployment):
  • Extends Continuous Delivery by automatically deploying every change to production once it passes all tests.
  • No human approval needed; new features or fixes go live quickly.

Hello Sdreatech,

• CI (Continuous Integration) ensures developers frequently merge code into a shared repository, where automated builds and tests run to catch bugs early, maintain code quality, and reduce integration issues.

• CD (Continuous Delivery/Deployment) automates releasing tested code to production (or staging), enabling faster, more reliable updates, reducing manual errors, and improving time-to-market.

By implementing CI/CD, teams deliver high-quality software faster, reduce risks of failures, and ensure continuous value delivery to users with greater reliability and efficiency.

Old Approach:
When a new program or version was ready, a programmer would package it themselves. They pointed to the source code location and handed over the executable file they had compiled on their own machine. The system trusted that the executable really came from that source code, but there was no way to guarantee it.

Now (with CI/CD):
The programmer only commits changes to the source code in version control. From there, the CI/CD pipeline takes over: it automatically compiles the code, runs tests, and produces the executable. Because the build comes directly from version control, we know the executable matches the exact code that was changed. The version control history also provides built-in documentation of what was modified and why.

About 40 years ago I wrote a promotion system. Currently the term that is more likely to be used is deployment. Programmers would specify where the source code is for a new program or a new version of a program. They would also provide the compiled executable that they created. The programmer was trusted to have built  the executable from the source code.

With CI/CD, software is automaticaly built and deployed. The programmer does not do the build and the built executables are known to have been built using the specified source code. The version control system even provides documentaion of the changes when a program is changed.

CI/CD (Continuous Integration and Continuous Deployment/Delivery) is a software practice where code changes are automatically tested, integrated, and deployed.

It matters because it helps teams deliver software faster, with fewer bugs, and more reliability, ensuring quick feedback and smoother releases.