One of the things I learned is that readability is a key part of scalability. One or two programmers can figure it out, but when you get to 20 or 30, if the code isn't clear, it costs time and money. Clever hacks need to go by the wayside, in favor of clear code.

As the saying goes "Always assume that the next guy to maintain your code is a psychopath who knows your address."

That is not something I knew in the early days of digg. I know it now.