[brandonb]

When you're as concerned with frontend performance as Google is, computer science knowledge can really come in handy. For example, they wrote their own compiler for Javascript to check for errors and shrink down the code to an absolute minimum, by e.g., shortening variable names and pruning functions that are never called. This means they had to write a their own parser, run various graph-based algorithms to follow references, iterate and transform the abstract syntax tree, etc.

http://code.google.com/closure/compiler/

[jumby]

And I'm sure the frontend guys were working on that.

Don't you think it's better to hire compiler experts for that exact problem rather than worrying about whether some frontend dude can write his own JS parser?

[dlo]

Someone who is working on the front-end without basic familiarity with computer science may not recognize such optimization opportunities and may not call a compiler expert in. Also, basic familiarity of computer science is useful for having the chops to validate an idea before wasting the time of an expert.