Javascript/jQuery optimization for large projects (social media)

Question

I am developing a social media website of the scale of LinkedIn, and I am struggling with few things related to JS. As project is going on, the requirement of JavaScript/jQuery is increasing. I am guessing by the end of the project, jQuery required on each page will be of average file size 1.5MB which is a bad idea. Functions like image upload, comments, like, updates is almost on every page.

My Question here is

Here I have already implemented: 1. Compress/Minify jQuery by PHP plugin
2. Use jQuery.getScript() to load file only when it required
3. Divide one large JS file into few separate files to finish loading faster
4. HTML optimization (Google Pagespeed)

Answer 1

I've heard of people using YUI Compressor, which 'has a better compression ratio' than most other tools. Not sure what you're using for compression at the moment, but this could provide a slight improvement. http://yui.github.io/yuicompressor/

Answer 2

Use a CDN (Content Delivery Network) to deliver jQuery. The browser will most probably cache the library and each page that loads, won't actually be needing to download the library again. This, if i'm not wrong, is one of the main reasons CDN's are used.

Otherwise, you should rethink your dependency/development strategy since you might not need jquery after all on each page. At least not whole of it.