If you want even lower resource usage, try honk[1] (currently using about 80M whilst my Pleroma is using 350M + 500M from Postgres) (although it is considerably more minimal than Pleroma...)
I love software like that, thanks for sharing. I do worry about seems like a single-user contributor project, though. Pleroma and Mastodon have healthy amounts of contributors and activity, so I feel more comfortable about going with them.
