Postgres has support for an eventually consistent in-memory caching layer?

Ha ha nice one - when your startup is Facebook you'll need that, not for your 12 users.

The reason startups get to their super kubernetes 6 layers mega AWS powered ultra cached hyper pipelined ultra optimised web queued applicatyion with no users is because "but technology X has support for an eventually consistent in-memory caching layer!!"

What about when we launch and hit the front page of HN how will the site stay up without "an eventually consistent in-memory caching layer"?