I personally know this timeline to be incorrect by at least a year. I was part of a startup that got acquired by FB in early 2015. We moved our codebase into th

I personally know this timeline to be incorrect by at least a year. I was part of a startup that got acquired by FB in early 2015. We moved our codebase into the FB monorepo pretty quickly. One of our microservices was written in Rust. It was only a few hundred lines, but it was in the repo and actively deployed on FB infra by April or so of 2015.