Where does the build come from?

Typically, a build comes from a CI/CD system (Continuous Integration/Continuous Delivery), such as Jenkins, GitLab CI, GitHub Actions, Azure DevOps, or TeamCity. After each commit to the repository, the CI/CD pipeline automatically builds, tests, and, upon successful testing, packages the artifact (build). The finished build is then placed in an artifact repository (e.g., Nexus or Artifactory) or directly delivered to testing or production environments.