[cmckn]

My recollection is that for a period of time, as a part of the internal “Move to AWS” (MAWS) campaign, the entire retail business ran within a single VPC. A lot has changed!

[spwa4]

That's crazy. That would never work unless these are just a VLAN configured on existing switches. Even VXLAN wouldn't be able to do that 5 years ago.

[UltraSane]

AWS developed their own custom overlay networking system. It embeds tenant IDs into the packets for isolation

[DevelopingElk]

Running out of IP addresses within that VPC is a real difficulty for services still using it.