2 posts tagged with "rust"

People assume four languages means four teams who couldn't agree, or four phases of a rewrite that never finished. Neither is true here. Fibe speaks Ruby, Rust, TypeScript, and Go on purpose, and each one is doing a job the others would do worse. The interesting part isn't the list — every grown-up system has a list. It's the rule that decides which language a given function lands in, and how boring we kept the seams between them.

This post is the honest version: what each piece is, why it exists, and the trade-offs we swallowed to get here. If you've ever stared at a monolith and wondered when to carve a piece off — and into what — this is one team's answer.

Fibe has been a Rails monolith since the first commit, and after a couple of years running a Docker-based dev-environment platform on it, we still think that was the right call. So when a small Rust workspace showed up in the repo, the obvious question — including from across the team — was some flavor of "oh no, are we rewriting in Rust?"

No. We extracted a very specific, very boring slice of the codebase into Rust, behind a rule we can state in one sentence. This post is that rule, why it works, and the genuinely annoying parts.