Depends what you want to do, 90% of what I code in is python or Ruby, and I'll switch to C when I want performance. I've done a lot of rails (Ruby), Django (python), and flask (python) work in web development. Much prefer rails, eaiser, and better thought out. I have several websites with hundreds of thousands of visits a year, it is fine (all the frameworks are). I have had to do some inline C to speed up my Ruby in a couple of instances - but that's very specific (and something you can easily do).

In terms of data science, python is my go-to and much more tooled for that kind of work. For any kind of desktop app I'll use C++, and for browser extensions / add-ons it's JavaScript.