"Learn at least 3 very different programming languages. I’d suggest C, Lisp and Python. The chances are that you will not find a Lisp job but it surely will make you a better programmer."
(I understand these are suggestions and we are in the realm of personal opinions).
Even as a Systems/Embedded programmer it's hard for me not to consider HTML/Javascript a must-have, this day and age (not a nice-to-have).
Even in embedded/industrial systems nowadays it's perfectly normal to have a maintenance interface based on a lightweight web server.
I still think C/C++ needs to be in the mix there somewhere(or even better, assembly). Even if you don't write them day-to-day knowing how pointers and memory works can be invaluable.
Chances are that you will need this but it's hard for me to recommend JavaScript as a starting point so it's actually a "must-have but a bit later" in my opinion.
(I understand these are suggestions and we are in the realm of personal opinions).
Even as a Systems/Embedded programmer it's hard for me not to consider HTML/Javascript a must-have, this day and age (not a nice-to-have).
Even in embedded/industrial systems nowadays it's perfectly normal to have a maintenance interface based on a lightweight web server.