I love that all the traffic is running through a single HAProxy box - a software load balancer (vs a hardware LB like F5).

And they've moved SSL termination to it.

That's a great quality product, and easy to setup.

Edit: I work I'm software that supports MySQL,PG and SqlServer. SqlServerr seems to be the most stable and consistent in performance - they're hard to kill! One of my few liked MS products :D