40.5 SEs, 2 UI, 3 PM, 5 TEST, 5 SRES, 2 managers
SE : System engineer, PM : Product Manager. Don't know what is SRES.
* Frontends: 5 machines per x users
* User DB : 30 machines per x users
* Conversation DB : 10 machines per x users
* Backend servers : 5 machines per x users
* GFS storage : 100 machines per x users
Total 150 machines per x users