Python, Go, PHP, Postgresql/Oracle/MySQL databases Little bit of algorithmic stuff in C++14.
In contract-work I do data-science with python/pandas/numpy while visualizing it with django or flask in the backend and d3/bokeh/etc. in the frontend.
In web development I love VueJS and MarkoJS in front while prefering python (fastapi/django/responder) or Go (no frameworks) in the back.
Already pretty advanced: Vue, Go, Graphql
Very basic (yet): Kotlin, Cython, Dart (Flutter more specifically)
projects and hacks
In my self employment I worked on calculating worldwide crop productions using the ApsimModel and automating/converting data (using pandas/python). Some might call it data mining.
At MPI I helped transition from php5.4 to php7.2 and migrate a lot of database code (which partly was written back in php4 days) to postgresql; introduced testing and modern git tools.