This is not strictly PHP, but it is about scalability, and every PHP programmer *ought* to be thinking about this stuff. Theo Schlossnagle of OmniTI (where I work as a web architect) has this slide deck posted about Scalable Internet Architectures.

Paul points out some highlights of the slides:

• Slide 7: "Lack of awareness of the other disciplines is bad."
• Slide 29: Know the difference between "premature optimization" and "necessary optimization".
• Slide 59: "Scaling is hard, performance is easier. Extremely high-performance systems tend to be easier to scale, because they don't have to SCALE as much."
• Slide 63: Combine this with slide 59, and you have the reason why you need to know your application responsiveness.

Being the founder and principal of a $6 million technology company is the crown jewel of Theo Schlossnagle's resume, but this is merely one of his many bragging rights. He is also a published author, the architect of a leading email software solution (www.messagesystems.com), and one of the IT industry's most in-demand speakers. And he's yet to turn 30.

Theo not only founded what became OmniTI (which employs several of the more well-known PHP developers including Wez Furlong, George Schlossnagle and Chris Shiflett) but is active in the PHP community itself, both as a developer and as an author - Scalable Internet Architectures.

Congrats Theo and best of luck!