Worked on the denoland/std repository to enhance semantic versioning controls by implementing configurable prerelease identifiers and explicit prerelease numbers in the version bump process. This involved updating the IncrementOptions interface in TypeScript to support specifying prerelease numbers, allowing for more deterministic and predictable versioning. Added comprehensive tests to cover scenarios where a prerelease number is set, ensuring reliability and correctness in the bumpPrerelease logic. Also addressed a bug that previously prevented users from setting a prerelease number during version increments. The work leveraged skills in semver, software development, and version control to improve release automation and user control.