Everything was seamless - I'd log in, tap my security key, and instantly have access to pretty much the entire monorepo and the rest of the production + deploy systems. All of the internal tools integrated with each other -- for instance, I could create a CL (i.e. a pull request) and then fix issues raised by the CI system, entirely from the IDE.
"Owning the stack" completely in-house also extended to hardware -- all of my builds happened inside Google datacenters too (not on my machine), and the development box they provided me was a Chromebook.