What is continuous integration and continuous delivery?

by Arthur Nielsen Demain and Chris Ching

Continuous Integration and Continuous Delivery (CI/CD) are two of the most commonly used words in software development, and both are essential in making the pace of a software delivery cycle as quick as possible by way of automation. With CI/CD, developers are released from some manual tasks to help them make their respective projects more innovative, whereas clients are able to receive regular project updates that give them the ability to provide more regular feedback on the developers’ outputs.

Let’s say that you are a team of five developers that is tasked to work on a project that’s expected to last for one year. Your team will not just say to the client, “Hey, we will just send an output to you after one year, see ya!”, will you? Obviously, your team must send regular chunks of output every two weeks, for example, to ensure that your client gets to review the quality of every single feature of the project that your team is expected to work on, and that your team is assured that you are delivering outputs according to your client’s expectations.

What’s the difference between CI and CD? Well, CI follows the “write, commit, test” approach. Here’s a simplified explanation: each developer in your team writes codes, then commits these codes into a central repository such as GitHub. Those commits in the repository then get tested if they will work or not. In short, a developer need not wait for a long time to submit what he or she has worked on to a central repository. A developer can just commit codes the moment he or she feels confident about them so that these codes can be automatically tested. Meanwhile, CD provides your team of developers a way to showcase the project you are working on in stages in a mock or simulated environment. If you are developing an app, then you can do a mock run of this app, or certain features of this app, using a mock server to give your client a preview of how certain elements will work. Doing this will give your team and your client the ability to refine the project until such time that it’s ready for full deployment.


CI/CD is now made easy, thanks to CircleCI, a company that will help you build quality projects rapidly, at scale. They will help you ensure that from the moment you commit up to the point of project deployment, everything is automated.

Here’s how it works:

VCS Integration

I mentioned about GitHub earlier. CircleCI is conveniently integrated with GitHub, GitHub Enterprise, and BitBucket. CircleCI will create a build out of the commits that you put into the repository.

Automated Testing

Your builds are automatically tested, each one of them, in a clean container or virtual machine. This gives you the confidence to come up with reasonably tested projects every single time!


Untested builds will be a thing of the past. Be assured that if your build encounters any issue, then you immediately get notified. This feature will help your team fix bugs quickly!

Automated Deployment

Once all is set, CircleCI makes sure that your project gets deployed to various environments to achieve greater market exposure.

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