Comment by singron

Also, Google's infrastructure is so vertically integrated that it's not obvious how to offer it others. E.g. Borg assigns 1 IP to each machine, which means every pod-equivalent has to listen on a dynamically allocated port, so Google eschewed DNS in favor of a system that more easily assigned dynamic IP:port pairs without relying on TTLs (BNS/Chubby). Google also decoupled storage from compute and had a bunch of custom databases to run in that paradigm (GFS/CFS/BigTable).