Honestly, is it that hard to make that thing from scratch? I mean Facebook started by just one student… and he didn’t had the technology available today.
Mastodon (https://github.com/mastodon/mastodon/) is built on Rails and appears to have taken 10k+ commits over several years to build. Comparable products include Pleroma (https://github.com/Hostdon/pleroma/), which has 12k+ commits, and Friendica (https://github.com/friendica/friendica) is a bit older, and has about 32k+ commits.
Based on those projects, I'd say the evidence suggests it's a fair amount of work.