Hi!
I released devpi-server 6.5.0 with mainly memory usage and performance fixes. I advice to also upgrade to waitress 2.1.1 which has related fixes.
I also released devpi-postgresql 3.0.0 which also reduces memory usage and I recommend installing it with devpi-server 6.5.0 for full impact of all the fixes, as some of them require changes made there.
Regards, Florian Schulze