[lib-dev]

If you require 500 instances of your app to scale, how do you get away with just a single DB instance?

[aeyes]

By having relatively simple queries. You can push 50k queries per second on a 64 CPU Postgres machine.

This is real world experience from a moderately complex application.

[jtc331]

It all depends on your workload. Those 500 instances may be make calls to other services, services, for example, or burning CPU in various ways.

[nickphx]

simple queries, grouping writes, minimizing updates, caching, connection pooling