Palo Alto, Skype
We are hiring to help us build massive distributed systems from the ground up on C#/F#/Azure.  We run elastic systems backed by a nosqlish data store, async replication, and, in general, do a lot of async programming.  We are doing devops, building systems to support Skype's amazing user base and move functionality, so our engineers get to do full lifecycle in an agile environment.  It is somewhat like a startup with a lot of money, food, dogs, but we do have a few more managers.  My team is smart, experienced, not risk averse, and in control of their own destiny.  You can't ask for much more than that.
Contact f00biebletch at gmail dot com for more great info.