Worked on improving macOS development machine provisioning for the modell-aachen/modac-dev-machine-setup repository, focusing on enhancing reliability and efficiency. Addressed a key provisioning bug by making asdf plugin installation idempotent, which prevented repeated installations and unnecessary reinstallation of Erlang and Elixir versions. Updated Homebrew package management to reference direct package names instead of relying on the homebrew/core tap, reducing setup errors and streamlining the provisioning process. Utilized DevOps practices, shell scripting, and YAML to implement these changes, resulting in a more robust and maintainable setup workflow for macOS development environments. The work emphasized stability and automation in system administration.