Succeed personally: no. Some dev jobs obviously require a lot of foundational knowledge. I wouldn't want to have a colleague who didn't know linear algebra, simply because that's important in my field. That's not important for making Wordpress sites. I think there are things "every good developer should know" such as knowledge about how cpus work, how OS'es work, how some important algorithms work, some basic set the…
I knew linear algebra in high school. I taught myself matrix math because I wanted to make games, and because the most challenging math my lackluster rural public high school offered was basic calculus. My top university's CS program had a linear algebra class that loaded me up with theory though like Hilbert spaces, wavelet transforms, spectral theory, abstract algebra, and of course, principal component analysis (b…
If the problem is related to web and databases and crap then there is rarely any linear algebra (heck there are rarely even real numbers) but we didn't go to school to work with databases and web forms did we ;)
Obviously hilbert spaces might not be useful everywhere but for example, anecdotally I did stumble across one interesting problem already in my first year out of university: A drawing program needed to scale a drawn ellipse in one direction, which wasn't necessarily along one of its axes. Q: is the result an ellipse? What are its axes?
A: (I had to ask a friend with better linear algebra skills, which still bugs me): the axes will be given by the eigenvectors of the matrix involved. The math was fairly hairy compared to most other things in a simple drawing program, but it was fun and really rewarding when the math worked.