Forget Platform and Tweak the Performance of "a Web Server"

Question

Unusual interview question I got.

Being completely agnostic about the platform, what are some things you can do to detect performance bottlenecks?

I mentioned examining CPU and memory to narrow it down to a problematic process, but got the hunch a better answer was expected.

Answer 1

Since no one else has thoughts, a really decent collection of tips here:

http://developer.yahoo.com/performance/rules.html