Programmer - often end up learning new things! So far, I could boast of:

OS: Linux, Mainframe (z/OS), UNIX, and yes, Windows as well.

Languages: Golang, Java, Python, C,C++,VC++, COBOL, VB, Easytrieve, JCL, SQL, Informix-4GL, REXX/CList, UNIX Shell-scripting, a little bit of R as well.

Databases: Oracle, MySQL, PostgreSQL, Informix, DB2, MongoDB and there were days when IMS too was listed in my skill-set!

Others: MQ Serices, CICS

...AND...whatever comes my way :)