Getting ready to launch: Front-end performance optimization

Thanks to Twitter I discovered a cool presentation by Ralph* (held on the RailsWayCon) about how to optimize the front-end performance of a web-based application. Although clearly targeted at a Ruby on Rails developer audience, Ralph's presentation contains many generally applicable techniques and methods.

Here are the ones I would recommend anyone to consider when doing web-based development and deployment:

1. User perceived load time of a web-site is determined 10% by the back-end and 90% by the front-end
2. YSlow (an add-on for the Firefox web-browser) is a tool analyse the (technical) performance of a web-site from the user's perspective; it gives a lot of good advice as well and covers many points mentioned in Ralph's presentation
3. Activate GZip to compress the output of your web-server before sending it down to the client (Apache: mod_deflate)
4. Smush.it is a good tool to determine how much you could get from optimizing your images (and it actually does it for you ;) )
5. The usage of multiple domains to serve content can speed up the user experience as most browser only download two files per domain at a time

Currently we - at mercadodeprevisoes.com.br - are evaluating and implementing some of these options for our portal - to enable the delivery of a smooth and fast user experience.

A German version of this post can be found in Carl's private blog.

* Disclosure: Ralph and I graduated together in Information Systems at the University of Münster.