Yes, it's possible and actually quite common to organize Buildbot configurations in a way that each project or branch has its own build recipe along with the source code. This approach helps in managing each project's build configuration independently, making it easier to maintain and update the recipes without affecting other projects.

Buildbot allows for flexible configuration, and the configuration file typically contains all the necessary details to define how the builds will run. These configurations can be centralized in one file, or you can split them across multiple files for better organization.

Currently, you may have a central buildbot.cfg or a similar file where all your projects and their build steps are defined. Instead of keeping everything in one place, you can split it by project/branch. To put each project’s build recipe with its source code, the most straightforward method is to create a buildbot directory inside each project's repository. This directory can contain a Python script that defines the build steps for that specific project. You can then reference this script in the central configuration or manage it independently.

Instead of having all the project recipes inside the central buildbot.cfg, you can import each project’s build.py in the main configuration file. This way, each project’s build logic is encapsulated within its own directory, and you simply call these recipes from the main configuration file. If you have the buildbot.cfg and each project's build.py under version control, you can commit and manage them independently. For example:

The main Buildbot repository would contain the buildbot.cfg and common configurations.

Each project repository would contain its own buildbot/ directory with build.py and other related configuration files.

This way, when you make changes to a specific project, you only need to update its build.py recipe, and you can ensure that each project’s configuration is versioned alongside its source code.

Once you've set up the project-specific recipes and the central configuration, Buildbot will pick up the individual recipes, trigger the builds accordingly, and execute the steps as defined in each project’s build.py.