the Expressions

After Effects expression engine is based on Javascript, but there are some minor differences. You can't include jQuery for instance.  I'm a front-end developer in my day job and to be honest I don't think you need to become one to use AE, it's just that if you know how to code in Javascript a little, then it helps.

For instance, if you want to break up a word and make changes to each letter, then something like:

var word = text.sourceText.split('');
for (var i = 0; i< word.length; i++) {
var letter = word[i]
// do something
}

Will help, but then again Javascript does not have wiggle(), time or linear() - so approaching AE as a pure front-end dev might not help.  The major benefit to AE using Javascript is that you can often find solutions on Stack Overflow 😄

TL:DR

Not really, but it doesn't hurt to know a bit