Hi Jason! Like many others here I'm looking forward to that blog post! :-)
For now, could you elaborate on what exactly you mean by transitioning from docker-compose to Nix? Did you start using systemd to orchestrate services? Were you still using Docker containers? If so, did you build the images with Nix? Etc.
When we used docker-compose we had a CLI tool which developers put in their PATH which was able to start/stop/restart services using the regular compose commands. This didn’t accomplish much at the time other than being easy to remember and not requiring folks to know where their docker-compose files were located. It also took care of layering in other compose files for overriding variables or service definitions.
Short version of the Nix transition: the CLI tool would instead start services using nix-shell invocations behind pm2. So devs still had a way to start services from anywhere, get logs or process status with a command… but every app was running 100% natively.
At the time I was there, containers weren’t used in production (they were doing “App” deploys still) so there was no Docker target that was necessary/useful outside of the development environment.
Besides the performance benefit, microservices owning their development environment in-repo (instead of in another repo where the compose configs were defined) was a huge win.
several nixy devtools do some process management now
something we're trying in Flox is per-project services run /w process-compose.
they automatically shutdown when all your activated shells exit, and it feels really cool