Why Continuous Integration Is Essential in Agile Development

The agile software development model requires continuous customer collaboration and adjustments as requirements change to help software evolve more quickly. That said, delivering code quickly doesn’t mean skipping out on quality.

The key is striking a balance between (1) meeting software requirements and estimates and (2) releasing code that is production-ready. If you neglect testing to make a deadline, you're increasing your technical debt and putting usability, security, and business success at risk.

I’ve written extensively about testing in the past, so I won’t belabor the point, but let’s talk about how tests are run.

Software tests can either be manual or automated. While there’s a place for some manual testing, it’s probably not possible to manually test your entire application before every single release.

So, most teams lean heavily on automated software testing, and automated testing is typically run as part of a continuous integration process.

What Is Continuous Integration?

Continuous integration (CI) is an iterative process where small sections of code are integrated into the application as they’re changed.

When followed, CI ensures that the desired feature or product has been built and that existing features weren’t disrupted by the change. CI is often paired with automated testing.

In this article, I’ll share more about the importance of continuous integration in agile development. I’ll also share a few tools that can help simplify and automate the process so your team can implement software changes without fear.

What Is Agile?

Agile methodology is based on evolving software quickly and delivering software at high frequency.

In an agile workflow, engineers typically receive requirements and break them down into user stories and tasks. Each task is distributed to a team member so that the team can complete the necessary work for each sprint.

Sprints are designed to deliver a defined feature (or set of features) and deploy them to a production environment.

While there’s a lot of other words and nuances to running an agile process, it all comes down to making smaller, faster releases than in a traditional, “Waterfall” process.

Benefits of CI for Agile

Continuous integration workflows can greatly improve an agile team’s chance of success because they streamline the compilation, testing, build, and release processes. By automating them instead of relying on error-prone, slow manual releases, CI can:

Increase Product Quality

Tests are a central component of a CI workflow. Unit tests and integration tests can both help improve code quality by catching errors before a build or release can proceed.

You can also automate some or all of your end-to-end (E2E) tests, which are used to verify functionality from an end user’s perspective. User actions can be simulated and run to ensure that the story outlined during the sprint planning process is actually fulfilled.

Maintain a Fast and Consistent Development Pace

Because CI helps make developers more confident in the code they write, it allows them to make changes faster, even on large teams.

Smaller changes and releases also prevent code reviewers from getting overwhelmed, giving them the opportunity to check that requirements are met and that the change was made in the best way possible.

When developers can fail fast, they can get to the correct solution faster and maintain a faster pace than teams not using CI.

Decrease Risk

CI practices allow for earlier detection of bugs and other missed requirements too. When bugs are introduced, the scope of the issue is usually more limited and easier to pinpoint. This allows developers to fix issues before delivering features to users.

Increase Team Productivity

When automated, a CI pipeline makes the development and testing process repeatable, saving software teams from repetitive manual work with each software update.

Teams can also use tools like Jenkins and Codecov to produce metrics around each build. Metrics may include build times, test coverage, and defect rates. This data can help teams identify problem areas in both code and workflows.

Improve Team Creativity and Culture

Finally, most software developers would rather spend their time innovating than doing mundane tasks.

It is in your company’s best interest to utilize the skillset their team was hired for instead of having them spend the majority of their time manually testing code.

By utilizing automated tests in a continuous integration workflow, developers will have more time to address user problems and experiment with solutions or architectures.

This allows developers to innovate, leads to improved job satisfaction, and further increases productivity.

Summary

Agile software development values fast, iterative software development processes that encourage quick releases of encapsulated feature sets. CI processes fit neatly into this goal. By integrating and testing code more frequently, developers can reduce risk and increase product quality.

Note: Thanks to Joanna Wallace, one of our writers at Draft.dev for her help researching this topic.