Hotmail at PDC 2005

This year at Microsoft’s Professional Developer Conference, PDC, Hotmail presented a case study on our Kahuna beta and how the underlying technology was built. One of our dev leads, Walter, gave a hour long talk that went over the latest builds that we had, the frameworks that we are using (including Atlas Bindings and FireAnt) and then invited people to join the beta. After talking to Walter and reading some blog posts, it seemed like there was a large amount of interest in the beta and in Hotmail being built using Atlas.

You can see some camera phone-esque screen shots from the presentation here. Apparently the slide deck has made it online and is available here. There are some great slides in the deck about FireAnt (our XMLHTTP framework) which I was a contributor to (the technology, not so much the deck). I’ll blog more about FireAnt soon, but if you want a good overview, check out Omar’s post on it.

I’ll also mention that we presented a bunch of interesting details about the Hotmail service, which gives you a good indication of the scale Hotmail operates at. Here are some fun ones:

  • ~200 million active users
  • 3.3 billion inbound emails a day
    • 1.5 billion blocked at the router
    • 1.0 billion deleted as spam (never hits the user’s mailbox)
    • 0.5 billion sent to the junk folder
  • Over 100 million messages sent a day
  • 80 – 100 milllion logins per day
  • 5000 peak logins per second