Hi there,
I'm Sergey Brester aka sebres and I am senior engineer, data scientist and security auditor.
My preferred langs are c, asm, c++, c#, tcl, python, ruby, but also js, php, scala, java, etc.
If I get time to open source, the main contribution belongs to:
TCL and its libraries and modules, and some other languages;
Fail2Ban (where I'm also key developer at the moment);
nginx, its modules and bindings, but also many other open-source projects.