Just checked out this video (links directly to m4v file) that someone forwarded to me earlier today.

Basically when trying to scale a rails app (or really any web based app) there are three core rules to live by.

1) Spindles = Bad. Talking to databases and/or file systems are slow.

2) Dynamic to static. Dynamic content is your enemy.

3) Push to the edge. Push everything as close to the client as you can.

"Rails scales exactly like any other web application... You need to take into account all the components, from the moment the request is received into the load balancer, all the way down, and all the way back again."

We're constantly working on improving performance on Fan Profiles as it continues to grow and have learned that these core rules are indeed the way to live by when working on scaling issues. Our work is far from done and likely will never be, but it's cool to see another sucessful rails team discuss these issues and how they tackled them.