What is continuous delivery?
Continuous delivery (CD) is a software development methodology that emphasizes automated testing, frequent code integration, and rapid deployment to reduce development cycle times. It enables software development teams to consistently deliver code changes to production with minimal manual intervention and promotes agility, collaboration, and reliable software releases.
A CD pipeline works by automating the entire process of deploying code changes. It builds on the principles of continuous integration (CI) to ensure that code can be released to production at any moment. Developers commit their code to a version control system, triggering automated tests and validations (the CI stage). If the code passes all tests, it’s automatically deployed to production or a staging environment (the CD stage). Combined, these two processes make up a CI/CD pipeline.
Continuous delivery vs. continuous deployment
Continuous delivery and continuous deployment are often used interchangeably, but there is a crucial difference in the extent to which the release process is automated: In continuous delivery, code changes are deployed to a staging environment but require manual approval to be released to users. In continuous deployment, code changes are deployed straight into production with no manual intervention.
The choice between continuous delivery and continuous deployment comes down to your organization’s risk tolerance, business objectives, and technical capabilities:
Organizations subject to strict oversight and compliance requirements may lean toward continuous delivery because it allows for more controlled and auditable releases.
Organizations that prioritize rapid feature delivery and are willing to accept slightly higher risk for faster time to market may opt for continuous deployment.
Teams that want to combine the speed and agility of continuous deployment with the additional control inherent in continuous delivery have a third option: progressive delivery. In progressive delivery, changes are automatically deployed into production but are hidden behind feature flags and gradually rolled out to a subset of users. This provides granular control over releases and gives teams an opportunity to gather real-world user feedback and performance data before a full release.
Benefits of continuous delivery
Software releases are notoriously complex, risky, and stressful. Keeping up with the pace of innovation depends on a robust CD pipeline.
Your business can’t afford slow, unreliable releases; adopt CD to outperform your competitors.
How CI and CD work together
Continuous integration and continuous delivery are complementary practices that work together to enhance the entire software development life cycle.
CI focuses on the frequent integration of code changes, automatically running tests to detect issues early in the development cycle. This ensures a codebase that remains stable and ready for deployment. CD builds on CI by automating the end-to-end delivery process, enabling automatic and reliable code deployments to various environments, including production.
Together, CI and CD create an efficient pipeline where code changes are continuously integrated, tested, and delivered, facilitating rapid and reliable software releases while maintaining code quality and stability. This collaborative approach improves development team productivity and ensures a consistent and predictable user experience.
Continuous delivery with CircleCI
CircleCI is the leading automation platform for world-class engineering teams. CircleCI supports continuous delivery practices by providing a robust platform and a set of features that enable development teams to automate and optimize their software delivery processes.