What is CI/CD? The complete guide

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CI/CD overview

CI/CD is an approach to software development that combines the practices of continuous integration (CI) and continuous delivery (CD) to make developing apps faster, safer, and more efficient. Through the use of automation, CI/CD helps teams detect, verify, and manage code changes from the moment they are introduced to the point at which they are released to customers. This system of change management is known as a CI/CD pipeline.

CI/CD pipeline diagram

CI/CD tools help teams eliminate the chaos and inefficiency that comes from multiple developers making changes to a shared codebase. They remove bottlenecks caused by manual, repetitive, and error-prone tasks and support effective software delivery through a culture of collaboration and continuous improvement.

CI vs CD (vs CD)

Continuous integration (CI) and continuous delivery (CD) are integral components of modern software development, but what exactly do these terms mean, and how do they differ? Let’s dive into the key concepts of CI, CD, and an additional approach known as continuous deployment (the other CD) to gain a comprehensive understanding.

Continuous integration (CI)

Continuous integration (CI) is the practice of frequently and automatically merging code changes from multiple developers into a shared repository. The key features of continuous integration pipelines are:

  • Automatic builds and tests: CI tools automatically build and test new code to identify any conflicts or errors. When problems are detected, developers are notified so that they can correct the issue early, before it escalates into more complex and costly challenges in later stages of the development cycle.

  • Rapid feedback: Continuous integration provides immediate feedback about the health and quality of your application after every change. This allows teams to make informed decisions, rapidly iterate on their code, and proactively address issues, resulting in more reliable, resilient, and customer-centric software products.

Continuous integration promotes a culture of agility, helping organizations optimize the development process, reduce waste, and quickly adapt to changing market conditions.

Learn more about continuous integration

Continuous delivery (CD)

Continuous delivery (CD) extends the CI process by ensuring code is always in a deployable state, allowing teams to release software at any time with confidence. Continuous delivery is often confused with continuous deployment, but there is a crucial distinction. A continuous delivery pipeline features:

  • Manual deployments: After successful testing, the release is packaged and staged, awaiting manual approval for deployment. A scripted deployment process may be in place, but it will not start until deployment is triggered by a designated approver.

  • Deploy-ready code: In continuous delivery, the code is always maintained in a state where it’s ready for deployment to production, but the actual deployment is triggered manually, providing a final checkpoint for human oversight and control before changes are released into the live environment.

Continuous delivery enhances collaboration between development and operations teams and reinforces confidence in the delivery process through heightened visibility and control.

Learn more about continuous delivery

Continuous deployment (CD)

Continuous deployment (CD) automates the entire software release process, from code integration and testing to deploying changes into the production environment. Unlike continuous delivery, continuous deployment requires no human intervention. A continuous deployment pipeline features:

  • Automatic deployments: Once the code passes all tests, it is automatically and immediately deployed to the production environment without manual approval.

  • Frictionless releases: Continuous deployment enables organizations to release software updates to customers as soon as they have been validated, reducing time to market.

Continuous deployment removes inefficient manual tasks from the delivery life cycle, accelerating time to market and creating a continuous flow of value to end users.

Learn more about continuous deployment

Benefits of CI/CD

Whether your organization adopts continuous delivery or continuous deployment, CI/CD is a game-changer for software development teams. It offers a multitude of benefits that can transform your development process.

Here are some key advantages
Rapid and reliable releases

CI/CD automates the deployment process, allowing you to release new features, bug fixes, and updates quickly and consistently. Say goodbye to lengthy and error-prone manual deployments.

Improved code quality

By integrating code changes frequently and running automated tests, CI ensures that issues are caught early in the development cycle. This leads to higher code quality and fewer bugs in production.

Enhanced collaboration

CI/CD encourages collaboration among developers, testers, and operations teams. It fosters a culture of communication and shared responsibility, leading to more effective cross-functional teams.

Greater visibility

CI/CD pipelines provide visibility into the status of code changes and deployments. You'll have real-time insights into the health of your software projects, making it easier to identify and address issues promptly.

Reduced risk

With automated testing and deployment, the risk of human errors is significantly reduced. This means fewer costly and time-consuming rollbacks due to failed deployments.

Faster time to market

CI/CD shortens the time between writing code and getting code into the hands of users. You can respond to market demands more rapidly and stay ahead of the competition.


As your projects grow, CI/CD scales with you. It can handle increased workloads, making it suitable for both small teams and large enterprises.

Continuous feedback

CI/CD provides continuous feedback loops, allowing developers to receive immediate information about the quality and functionality of their code. This iterative process fosters continuous improvement.

Predictable deployments

With CD, you have the option to automate or manually approve deployments to production. This means you can choose the level of control that suits your organization's needs.

Cost efficiency

By reducing manual intervention and error rates, CI/CD can lead to cost savings in the long run. It optimizes resource utilization and minimizes downtime.

Incorporating CI/CD into your software development workflow unlocks the potential for more efficient, collaborative, and reliable software delivery.

DevOps and CI/CD

Optimizing your software delivery process goes beyond simple automation. It requires the fusion of culture, collaboration, and cutting-edge technology. DevOps, an agile and holistic approach to software development, is at the heart of this transformation.

Where CI/CD focuses on the technical aspects of validating and delivering code changes, DevOps also encompasses organizational and cultural changes, aiming to break down traditional silos between development (dev) and IT operations (ops) teams. It encourages ongoing communication, feedback, and accountability to drive efficiency, reduce toil, and deliver better software outcomes.

DevOps infinity loop

In the past, development teams focused exclusively on producing working code, with little concern for how operations teams could deploy and maintain the application in a production environment. With the help of CI/CD, DevOps introduces a “shift left” mentality that encourages developers to take responsibility for the quality, performance, and more recently, security (a practice known as DevSecOps) of their code in a production setting.

CI/CD is a crucial component within the DevOps framework. It provides the technical foundation to support the broader cultural shifts required to embrace the DevOps mindset.

With the right CI/CD tools in place, DevOps teams can improve the speed and reliability of software delivery and align team practices in service of shared business goals.

Learn more about DevOps >

CI/CD with CircleCI

CircleCI is the leading CI/CD platform for world-class DevOps teams. With the largest selection of cloud-hosted environments and the broadest range of integrations, CircleCI gives you the power and flexibility you need to overcome today’s software delivery challenges. Optimize your workflows, secure your sensitive data, and deliver better customer experiences with the fastest, most reliable CI/CD platform on the planet.

CircleCI customers outperform the competition with the help of these features:

  • Speed: CircleCI runs CI/CD workflows faster than any other CI/CD tool, hands down.

  • Security: Built-in security and compliance tools and seamless integrations let you lock down your data and eliminate vulnerabilities with ease.

  • Flexibility: Build where you want, with the tools you want, and customize your workflows to meet any use case.

  • Scalability: Start with a plan that suits your current needs and be confident your pipelines will deliver the same performance as you grow.

  • Support: Get personalized help with onboarding, optimization, and troubleshooting from a team of CI/CD experts.

Get started with up to 6,000 free build minutes per month and put the power of intelligent automation to work in your organization. Sign up for a free account or contact us for a customized demo. Find out how industry-leading CI/CD with CircleCI can deliver better software and better business outcomes today.