codebase
/ˈkəʊdˌbeɪs/noun
A codebase is the collection of source code used to build and maintain a software product or component.
Before building the new feature, we examined how the existing codebase was organized.
A codebase comprises code that developers manage as a whole. It can cover an entire application, a separate service or a Glossary · In brieflibraryA library is a collection of reusable software code for a defined task. An application can call that code to use existing functionality.Read more. Size says little about quality: a small codebase can be difficult to understand, while clear conventions can keep a large project maintainable.
What belongs in a codebase?
Alongside source code, a codebase usually contains files needed to build, test and configure the software. These include tests, scripts and development environment settings. Generated files and installed Glossary · In briefdependencyA dependency is a software component or system that other software needs in order to build or run, such as a library, framework or external service.Read more are generally excluded because they can be recreated or downloaded again.
A codebase is not exactly the same as a repository. A repository stores files and their history using Glossary · In briefversion controlVersion control records changes to code, including who changed what and when. It lets developers collaborate, compare changes and return to an earlier version.Read more. A codebase often lives in one repository, but an application can combine code from several repositories. Conversely, a repository can contain documentation or other files outside the codebase.
Working on an existing codebase
Anyone taking over a codebase first needs to understand how its parts fit together and which conventions the team uses. Tests, documentation and a recognizable folder structure help. The Glossary · In briefframeworkA framework is a coherent foundation for software development, providing reusable code, a defined structure and conventions for building an application.Read more and dependencies also determine how much prior knowledge is needed.
The codebase grows and changes as development continues. Glossary · In briefrefactoringRefactoring changes the internal structure of existing code without changing observable software behaviour. The aim is to make code easier to understand and modify.Read more keeps its structure understandable without changing its intended behaviour. Temporary solutions and deferred maintenance can create Glossary · In brieftechnical debtTechnical debt is the extra work required because earlier software decisions make later changes harder, slower or riskier.Read more, making later changes more time-consuming or risky. Code reviews and automated tests help catch errors and unclear changes early.