Johann contributed to both the idris-lang/Idris2 and Nitrokey/nitrokey-documentation repositories, focusing on stability and maintainability. In Idris2, Johann engineered a thread-safe final garbage collection mechanism by introducing a collect-rendezvous approach, which pauses all threads before shutdown to ensure deterministic garbage collection in multi-threaded environments. This addressed a termination-time bug and improved runtime reliability. For Nitrokey documentation, Johann unified RST documentation links to always reference the latest udev rules in the canonical repository, reducing configuration drift for Linux users. Across both projects, Johann applied skills in concurrency, garbage collection, documentation, and link management, working primarily with Idris and RST.