There were two things I knew about eBay's Architecture - that they use J2EE and that they seem to like SOA. Both are approaches I give, ahem, special mention to on all my pages at the bottom of the left-hand column.

So it was with some apprehension that I opened up this (PDF) slide pack from Dan Pritchett and Randy Shoup of eBay, presented at SD Forum 2006 recently. I was expecting my prejudices around the issues and techniques of scaling web sites to be challenged, at least.

Instead, I found one after another of my scaling beliefs met. There was, indeed, a mention of J2EE - specifically the one where they said they threw most of it out! And a mention of SOA - the tiny line between two boxes on one slide connecting the 'Transaction Platform' to the 'Fraud' system!

The rest of the slides talked about sensible engineering practices such as cacheing, partitioning, statelessness, event-driven architectures and horizontal scaling. I was surprised to see XSL mentioned at the front end but, hey, it's a Declarative technology - so I'm not complaining!

It's a must-read document for anyone considering scaling a website. As it happens, I'm currently considering scaling a Web 2.0 site for a client at ThoughtWorks, so it's really put me in the right frame of mind. There's a summary of the talk by Johannes Ernst if, like me, you resist clicking PDF links.

Dan, of course, is the eBay Architect who has responded to the first two episodes of my REST Dialogues. I recommend his blog - even to the SOA-averse!