What is the difference between continuous integration and continuous delivery?

1 Continuous integration

Continuous integration (CI) is the practice of merging all the code changes from multiple developers into a shared repository frequently, usually several times a day. This allows you to detect and fix errors early, and ensure that your code is always in a working state. To implement CI, you need to use tools that automate the building, testing, and verification of your code, such as Jenkins, Travis CI, or GitHub Actions. CI helps you avoid integration conflicts, reduce bugs, and increase collaboration among your team.

2 Continuous delivery

Continuous delivery (CD) is the practice of releasing your code to production in small and frequent increments, instead of waiting for a big launch. This means that your code is always ready to be deployed, and you can deliver value to your customers faster and more reliably. To implement CD, you need to use tools that automate the deployment, monitoring, and feedback of your code, such as AWS CodeDeploy, Heroku, or Azure DevOps. CD helps you reduce risks, improve customer satisfaction, and respond to changes quickly.

3 The difference

The main difference between CI and CD is that CI focuses on the quality of your code, while CD focuses on the delivery of your code. CI ensures that your code is always tested and validated, while CD ensures that your code is always deployable and releasable. CI is a prerequisite for CD, but not vice versa. You can have CI without CD, but you cannot have CD without CI.

4 The benefits

Both CI and CD offer numerous advantages for both your software development process and business outcomes. You can get faster feedback on your code quality and functionality from automated tests and tools, as well as from customers and stakeholders. This can help you catch and fix errors early, preventing them from reaching production. Additionally, you can save time and resources by automating your build, test, and deployment processes while reducing the complexity of managing large and infrequent releases. Moreover, CI/CD makes it easier to experiment with new features and ideas, test them with real users, and adapt to changing requirements and market conditions quickly.

5 The challenges

While CI and CD can bring many advantages, they also come with some challenges. To start, you need to foster a culture of collaboration, trust, and accountability among your team and organization. Additionally, mastering the tools and technologies that enable CI and CD is necessary, such as version control, automation, cloud computing, and security. Furthermore, you must define and follow clear and consistent processes for your CI and CD pipelines. This includes code reviews, testing strategies, deployment policies, rollback plans, as well as monitoring and measuring your performance and results. Lastly, it is important to embrace change, feedback, and learning as part of your daily work to stay up-to-date with the latest trends and best practices in your field.

6 The best practices

To succeed with CI and CD, you need to follow certain best practices that can help you overcome the challenges and maximize the benefits. Regular communication and collaboration with your team and stakeholders is essential, as well as automating and standardizing processes and using tools that integrate well with each other. You need to test and verify your code thoroughly and frequently, using different types of tests such as unit, integration, functional, and performance tests. Additionally, deploying and monitoring your code continuously and incrementally is necessary to measure and improve outcomes. All of this will ensure your code meets quality and security standards, complies with business and user requirements, delivers value to customers, and aligns with your strategy and vision.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?