Continuous Integration and Deployment (CI/CD) provide an automated process to build, test and package software. CI is the first step and CD takes over where CI ends so that code changes can be deployed to production environments as they are ready.

Less risky deployments mean happier users and customers. Having an automated build process makes it easier for teams to find and fix errors quickly and easily.

Build

Continuous integration (CI) is the process of integrating small changes to an application into the main branch of code frequently, as often as several times per day. This ensures that any new build will not break the existing codebase and allows developers to make fixes without having to wait for an entire batch of changes to be built and tested. It also helps development teams avoid building on bad foundations, which may cause bugs and functionality issues later on.

With the help of automated testing tools, every new build is then validated against a set of criteria and test cases that will confirm whether it can run successfully in production. This step is critical, because human testing is often too slow and prone to errors and oversights to provide reliable and objective results for every build. This is why the CI/CD pipeline relies heavily on automated tests to get the job done.

The next stage of the CI/CD pipeline is continuous deployment, which automates the process of pushing completed builds of software to environments like production and testing. If a build passes all the previous stages of the CI/CD pipeline, it can then be automatically deployed to production so that users can start using the new release as soon as possible. This step is usually accompanied by various deployment practices, such as canary releases or blue-green deployments, to help manage the rollout and minimize any potential issues that may arise.

Test

Continuous integration is the practice of merging all developers’ changes to a shared mainline several times a day and running automated testing. This ensures that the code everyone is working on doesn’t break the entire application.

For compiled languages (like Java and Python), this means checking that the code compiles successfully. For non-compiled languages, this might mean running unit tests or a regression test suite to see whether the new code introduces any bugs or performance problems.

When a developer’s change passes automated testing in CI, they can move on to the next step — continuous deployment. This process automates the release of code to a production environment for testing and customer use. It takes the stress out of releasing software to customers by removing the need for manual steps like creating a build and installing it on a server.

This allows developers to focus on building quality and helps teams to shorten the feedback loop with their customers. It also allows developers to work on features in small chunks and see them go live in production more frequently. For companies that have a well-functioning CI/CD pipeline in place, this can be as simple as clicking a button. Deployment practices such as canary releases and blue-green deployments can help minimize risk and manage the rollout of a new feature.

Deploy

Continuous integration and deployment help teams release valuable, working software on a more frequent basis. They speed up the feedback loop with customers and automate repetitive tasks. CI/CD practices can be difficult to get started with but with some guidance from experienced professionals it’s a lot easier than many think.

CI involves merging all developers’ work into a shared mainline code build at least once a day (ideally several times per day). This ensures that the code individual developers are working on does not divert too far from the latest version of the product. Combined with automated testing, this makes for more reliable code.

After a build passes the tests it is ready to be deployed. Continuous deployment takes this a step further by automatically deploying changes to production, once they pass all the tests and are ready for release. This makes it possible to roll out small batches of code to users daily, weekly or on a schedule that suits the business.

Continuous deployment requires a strong foundation in continuous integration and a robust test suite. It is also a good idea to adopt other DevOps deployment practices such as canary releases or blue-green deployments to minimize risk and control the pace of roll out. Developers may also need to learn how to use feature flags so that incomplete features do not affect end-users in the early stages of the roll out.

Release

Continuous integration and deployment are connected practices that help teams release software faster and more reliably. Each step builds on the previous to streamline the entire development cycle and automate key steps. Continuous integration (CI) involves merging developers’ code changes into a shared source code repository frequently, usually several times a day. This allows for small changes to be incorporated into the build more easily and helps avoid problems during the final merge needed for a production release.

This stage then triggers automated tests to verify that the integrated code works as intended, and it can catch a lot of bugs and errors before they make it into production. If the tests pass, then continuous delivery (CD) can deploy the code to production environments automatically.

CD can be set up to release changes daily, weekly, fortnightly, or whatever schedule suits your business requirements. However, to achieve the maximum benefits of continuous deployment, it’s advisable that you limit releases to small batches so that any glitches can be easily troubleshot.

Continuous deployment is the next step in a CI/CD pipeline and automates the release of any validated code changes from a source code repository into a production environment. This stage can also deliver updates to existing features, bug fixes, and new functionality to users without any human intervention.