CI/CD/CD

The components of this approach can be used separately (CI or CI + CD) or one after another as a single process (CI + CD + CD).

What is CI/CD?

Continuous integration (CI)

Each integration is then automatically built and tested, which helps detect and fix conflicts and bugs. CI improves software quality and stability and shortens the release cycle. CI is usually implemented with a CI/CD tool that automates building, testing, and deployment. By automating these tasks, CI/CD helps reduce manual errors and increase efficiency, so teams can focus on building new features and improvements.

Continuous delivery (CD)

Continuous delivery is CI + CD, the next level after CI. Now a new version is not only built and tested every time a code change is committed to the repository, but it can also be released quickly with a single click of the deploy button. However, the deployment is still triggered manually: someone still has to press that button. This method lets teams release changes in small batches that are easy to modify or roll back if needed.

Continuous deployment (CD)

Continuous deployment is CI + CD + CD. Once the release is automated, only one manual step remains: approving and triggering deployment to production (that very button). Continuous deployment removes this step too, so no direct approval from a developer is required. All changes are deployed automatically.

Continuous testing (CT)

Unlike the traditional approach, where testing happens after development is complete, CT is built into the CI/CD pipeline:

• Tests run automatically on every code change.
• Different types of tests run in parallel.
• The development team gets fast feedback.
• Testing is integrated with monitoring and quality analysis systems.

CI/CD principles

Continuous delivery rests on a number of fundamental principles that help organizations build a reliable and efficient delivery pipeline. They include:

Build reliable, repeatable processes

To minimize errors and keep deployments stable, every stage of the pipeline, from code integration to final deployment, should be predictable and reproducible.

Run tests in parallel

To check software quality and security, run different types of tests at the same time: unit tests, integration tests, load tests, security scans, and others. Parallel testing shortens the feedback loop so teams can find and fix issues early in the development cycle.

Prioritize stages with fast feedback

The sooner the team learns about problems, the less time and effort it takes to fix them. That's why the key quality checks should run early in the process.

Design flexible processes

The delivery pipeline should adapt to changes in parameters, configurations, and requirements while keeping deployments stable. Flexibility helps the team respond quickly to new challenges and maintain a high delivery pace.

Focus on feedback

It's important to collect feedback from different sources: automated tests, code analysis, and user testing. This helps the team spot bottlenecks quickly and prevent failures.

Benefits of CI/CD for business and development

Besides the obvious benefits of faster time to market and easier rollout of updates, CI/CD offers several other advantages. Let's look at them more closely.

Attracting strong developers

With fierce competition for skilled engineers, a high salary alone is not enough. Developers want to work on strong teams with mature processes and tools. A well-established CI/CD practice shows candidates that the company takes engineering seriously and cares about its developers' working conditions.

Better teamwork

Building complex software requires many specialists to work in sync. CI/CD makes collaboration easier by automating routine tasks. Developers can concentrate on their own work, while continuous integration into a shared repository keeps the product consistent.

Higher reliability and efficiency

CI/CD principles ensure not only the speed of releases but also their quality. Automated tests check every code change before it goes to production. Monitoring tools quickly reveal the root causes of errors, and regular reliability checks keep code quality under control as changes are introduced. Fixing non-critical defects promptly reduces technical debt.

Better user experience

Fast, regular updates make it possible to add new features and fix bugs quickly. Users value products that evolve with their needs. CI/CD helps teams respond to feedback quickly and adapt to market changes, keeping their solutions competitive.

Automated tests and continuous monitoring built into the process help catch problems before users run into them. This makes products more stable, strengthens customer trust, and improves the company's reputation.

Faster return on investment

The key business metric is how fast the team creates a valuable product. CI/CD shortens development and deployment cycles so new features reach the market sooner. This agility helps companies stay ahead of competitors and seize new opportunities quickly.

Less burnout

Software development requires constant focus, and pressure from deadlines and issues often leads to burnout. CI/CD reduces the load by automating routine and complex tasks. Developers can focus on the creative part of their work instead of manual testing and deployment.

Fast recovery from failures

CI/CD gives teams the tools to respond to incidents quickly and minimize their impact on users and the business. When a problem occurs, the team can quickly roll back to a stable version of the product, reducing downtime and customer frustration.

Tools and technologies for CI/CD

Continuous integration lets development teams regularly introduce and test small, incremental code changes, which are then merged into a shared repository in a version control system. An automated build verifies these changes so code issues can be found and fixed quickly. With CI, several teams can work on the same application at the same time without conflicts.

Here are the main capabilities of continuous integration:

Controlling access to new code

Although continuous integration merges changes automatically, not every update should be available to users right away, for example, unfinished features.

Feature flags are used to control access to code. With them, developers can mark new pieces of code that are ready for testing. This approach reduces risk when changes need to be rolled back.

Automated testing

Test automation is an essential part of continuous integration. It lets developers change code more often and improve its quality without slowing down development.

Automated tests guard against changes that could break the application. As an added benefit, automatically generated test coverage reports help assess how effective the tests are.

Prioritizing fixes

Application code can be complex and tangled, so failures are inevitable. It's important to decide which fixes need immediate attention and which can wait. Since failures are often fixed reactively rather than proactively, there is usually little time to weigh priorities.

Continuous integration tools help find issues faster and make it easier to decide which fixes come first, so critical problems get resolved sooner.

How does CI/CD relate to DevOps?

CI/CD enables fast and reliable delivery of code and applications. This approach has become an integral part of many methodologies, systems, and tools, including DevOps.

DevOps brings together software development (Dev) and IT operations (Ops). It is a practice in which IT, development, security, and quality assurance specialists work together to build the product and improve the service users receive. DevOps is based on Agile principles and aims to shorten the development cycle while keeping software quality high.

CI/CD naturally complements DevOps. CI/CD pipelines let developers make changes quickly while keeping applications stable. Done right, CI/CD improves key DevOps metrics: deployment frequency, lead time for changes, and time to restore service after a failure.

A typical CI/CD workflow

Although the approach to CI/CD varies by organization, project, and tools, a standard process usually includes the following steps:

• Creating a CI/CD pipeline. The pipeline describes the sequence of steps developers follow to deliver finished software. A basic CI/CD pipeline consists of source, build, test, and deploy stages.
• Automating the CI/CD pipeline. At this step, the team connects the pipeline to version control and source code systems and sets up all pipeline steps to run automatically.

SimpleOne for CI/CD

CI/CD has become an essential practice that helps organizations quickly build reliable software that meets users' expectations. To get the most out of CI/CD, teams also need a clear view of the work that flows through the pipeline. SimpleOne SDLC helps development teams plan, prioritize, and track that work using Agile methodologies.