You mean like Teslas multi terabyte repo is not normal?

I think it's obvious that multi terabyte repos are not the norm.

How did they even manage to generate a terabyte sized repo, that's crazy. Do they have something written up on how it's structured and why they'd even go that route?

A terabyte is ~220 thousand books (1000 pages, 50 rows, 100 columns) uncompressed. VCS generally store objects compressed.

It couldn’t be broken in to domain specific components?

Listen, I am a rails developer, so a monolith doesn’t scare me, and yet, there are limits. Why does it need to be a multi terabyte monolith?