CI/CD (Continuous Integration/ Continuous Delivery or Continuous Deployment)

The main concepts attributed to CI/CD are continuous integration, continuous delivery, and continuous deployment. A method to frequently deliver apps to customers by introducing automation into the stages of development.

They're practices in software development that allow teams to build projects together quickly, efficiently, and ideally with less errors.

Continuous integration is an automation process for developers. Successful CI means new code changes to an app are regularly built, tested, and merged to a shared repository.

• Solution to the problem of having too many branches of an app in development at once that might conflict with each other.
• Once a developer’s changes to an application are merged, those changes are validated by automatically building the application and running different levels of automated testing, typically unit and integration tests, to ensure the changes haven’t broken the app.

Continuous delivery usually means a developer’s changes to an application are automatically bug tested and uploaded to a repository (like GitHub or a container registry), where they can then be deployed to a live production environment by the operations team.

• Solution to the problem of poor visibility and communication between dev and business teams.
• Continuous Delivery mean that the feature code has been tested and ready for deployment but it is also deployed on a mock server to check it before deploying it on main server.

Continuous deployment (the other possible "CD") can refer to automatically releasing a developer’s changes from the repository to production, where it is usable by customers.

• It addresses the problem of overloading operations teams with manual processes that slow down app delivery.
• Continuous deployment means that a developer’s change to a cloud application could go live within minutes of writing it (assuming it passes automated testing). This mean directly deploying the updates on main server.

<aside> 📔 Case-by-case, what the terms refer to depends on how much automation has been built into the CI/CD pipeline.

</aside>

Continuous Integration is the idea that as different members of the team work on code on different git branches, the code is merged to a single working branch which is then built and tested with automated workflows.

• This helps to constantly make sure everyone's code is working properly together and is well-tested.

Continuous Deployment takes CI a step further and takes the automation to the deployment level. Where with the CI process, you automate the testing and the building, Continuous Deployment will automate deploying the project to an environment.

• The idea is that the code, once through any building and testing processes, is in a deployable state, so it should be able to be deployed.

Branching strategy

Nowadays, there are many workflows: Git flow, GitHub flow, GitLab flow, Trunk-based development, etc.