

In theory, they can. But it depends on how it’s deployed.
From my cursory look at the deployment docs, Lemmy’s default deployment option is via docker. It relies on a postgreSQL server, which may or may not scale horizontally depending on the admin’s choice of implementation. For example, a deployment on AWS using Aurora would theoretically utilize auto-scaling.
I haven’t personally deployed an instance so, grain of salt.
EDIT: A good discussion about DB scaling here: https://github.com/LemmyNet/lemmy/issues/3005
This is a duplicate comment.