I'm not sure it's wise to spill the beans, but Cesar and his team are Service Bus' best-kept secret. Until today, that is.
Like most teams at Microsoft we have a dedicated test organization. Very early on, when Service Bus was a one-machine open CTP running on a box under someone's desk (literally) and then on two machines in a test lab, we had some overinflated confidence on what it would take to ship a service. Then Cesar showed up with complete team and took the air out of that confidence balloon -- and then helped building confidence back up to the point that we can sleep very well while being on-call with 8 datacenters running key customer workloads on Service Bus.
Test owns checking claims and aspirations against reality, and a lot more. Watch this one.