Sometimes I really do not know what I am doing wrong when applying for jobs.

Latest example is https://canonical.com/careers/5140562

I told them I am the co-creator of the entire software stack behind https://mod.audio/dwarf/ (even talking about this device on their conference next month).
Also that I am the maintainer of the KXStudio repos, so have experience with deb packaging.
Plus extensive C/C++ knowledge as seen on my portfolio at https://falktx.berlin/portfolio/

Rejected within 1 day, not even an interview 🤷‍♂️