For instance, I was making my first mobile web-application about a year ago, and half-way through, someone pointed me to jQuery Mobile. Obviously this induced a total revolution in my app. Rewrote everything. Now, if you're in the field long enough, maybe that seems like common knowledge, but I was totally new to it.

But this set me wondering: there are so many libraries and extensions and frameworks. This seems particularly crucial in the category of security. I'm afraid I'm going to find myself doing something in a professional setting eventually (I'm still a student) and someone's going to walk over and be like, My god, you're trying to secure user data that way? Don't you know about the Gordon-Wokker crypto-magic-hash-algorithms library? Without it you may as well go plaintext.

How do you know what the best ways are to maximize security?

Especially if you're trying to develop something on your own...