Strategies for improving code quality in large codebases
Published: 2023-05-08 19:15:39

Code quality is crucial for any software project, but it becomes even more critical as codebases grow in size and complexity. When working with large codebases, it can be challenging to maintain consistent code quality, avoid bugs, and ensure that new changes don't introduce regressions.

Poor code quality will slow down your development process over time. Instead of being able to focus on delivering new features, you'll likely find yourself spending a significant amount of time dealing with technical debt.

In this post, we'll explore strategies that can help improve code quality in large codebases. Whether you're part of a large development team or working solo on a substantial codebase, these strategies can help you ensure that your code is maintainable, efficient, and reliable.

## Code reviews
Code review involves having one or more developers review changes made by another developer before they are merged into the main codebase. Code review can help catch bugs, improve code readability, and ensure that coding standards are being followed. By catching and addressing issues early on in the development process, code review can help prevent technical debt from accumulating and improve the overall quality and stability of the codebase.

Code review is a collaborative process, where reviewers and developers can discuss and work through any issues that arise. By fostering a culture of constructive feedback and collaboration, code review helps engineers build better relationships and work together more effectively.

To make the most of code review, follow the best practices:
- **Keep your changes small** to make them more manageable for reviewers. Code review should ideally take no more than a couple of minutes per each change. If your changes are too big, consider breaking them down into smaller pieces for easier review.
- **Have a test plan in place to verify that your solution works**. This can include automated tests, screenshots, or even a video demo.
- **Provide constructive feedback**. The goal of the reviewer should be to improve the solution, not criticize it. Use a positive tone and consider asking questions instead of making statements. Additionally, don't forget to celebrate good code when you see it. This will help foster a positive culture and make the code review process more pleasant for everyone involved.
- **Ensure that everyone on the team participates in code review**, regardless of their level of experience. This not only ensures that code quality is maintained across the entire codebase but also encourages engineers to write better quality code knowing that their work will be reviewed.
- **Make the review process as fast as possible** to avoid frustration and delays. Ideally, code reviews should be completed within a day, not several days or more. If necessary, consider talking to the change owner in person to speed up the review process.

Finally, stay positive and foster a positive culture around code review. By creating a supportive and collaborative environment, you'll help your team appreciate, rather than viewing it as a chore or a source of stress.

## Tests
Engineers won’t be able to find every error that might occur due to the changes by manual testing. Over time it becomes almost impossible to catch regressions or bugs as the codebase grows and changes over quickly.

To make the development process more efficient you can leverage automated tests. Tests can catch bugs and regressions in the early stage in the development process before they become more difficult and expensive to fix. Make sure that tests are running automatically after each change, ensuring that the system continues to work as expected.

Writing automated tests can be time-consuming, but it can save time in the long run by reducing the amount of manual testing that's required. By automating your tests, you can quickly and efficiently test your code as it changes and evolves, freeing up time to focus development work.

While it's important to have tests for your codebase, it's also important not to go overboard. Some teams try to cover 100% of the codebase with tests, or use TDD to write tests for every function before implementing a feature. Try to find a balance and ensure that writing and maintaining tests doesn't become overwhelming for the team.

Rather than trying to test every possible scenario, focus on critical flows or those that have historically caused problems or confusion. This will help ensure that your tests are targeted and effective, rather than becoming a burden for the team.

## Code style and standards
Having a consistent style not only makes it easier for developers to read and understand the code, but it also helps maintain code maintainability and reduces the likelihood of bugs.

One way to ensure consistent code style is to adopt a style guide or standard. A style guide is a set of guidelines that define how code should be written, including formatting, naming conventions, and other best practices. There are many style guides available for different programming languages and frameworks, such as Google's JavaScript style guide or the PEP 8 style guide for Python. Adhering to a style guide can help ensure that all code is written in a consistent style, regardless of who wrote it.

In addition to adopting a style guide, it's important to enforce the standards and guidelines in your codebase. This can be done through the use of linters or other automated tools that check code for adherence to the style guide. Many code editors also have built-in tools that can help enforce coding standards, such as auto-formatting code to match the style guide or highlighting violations of the style guide.

It's also important to ensure that all developers in the team are aware of the coding standards and understand why they're important. This might involve conducting training sessions or including the style guide as part of the onboarding process for new developers. It's important that all developers understand the rationale behind the coding standards and how they contribute to maintaining code quality in large codebases.

## Documentation
Documentations are often overlooked or neglected in favor of writing code. However, well-written documentation can be a valuable resource for developers to understand how the code works, what it does, and how to use it. It can also save time and reduce confusion in the future.

You can start by writing clear and concise comments in the code. Comments are a quick way to provide context and explain the purpose of a particular code block. However, comments that are too generic or irrelevant can be just as distracting as no comments at all. Make sure your comments are clear, concise, and relevant to the code.

As your codebase gets more complex, consider creating a separate document that describes the architecture, design decisions, and workflows of the project. This can serve as a useful reference for developers who are new to the codebase or who need a refresher on how things work.

Keep documentation up to date. Documentation should be treated as a living document that evolves with the code. Make sure to update documentation when changes are made to the code, and encourage team members to contribute to and improve the documentation as needed.

## Conclusion
In conclusion, improving code quality is a continuous process that requires discipline, collaboration, and the use of appropriate strategies. We have discussed several key strategies for improving code quality in large codebases, including code review, automated testing, using a code linter, and enforcing code style and standards. We have also emphasized the importance of documentation in maintaining and improving code quality over time.

By implementing these strategies, teams can reduce technical debt, improve development speed, and maintain the integrity of the codebase. However, it's essential to keep in mind that these strategies are not one-size-fits-all, and teams should adapt them to their specific needs and constraints.

Improving code quality is not only about producing better code but also about fostering a culture of collaboration and continuous improvement. By investing in code quality, teams can improve developer satisfaction, reduce bugs and errors, and ultimately provide more value to their customers.