At Airbnb we are implementing translation serving on top of Sparkey; part of our Ruby system open sourced here: https://github.com/airbnb/hammerspace

The way the system worked (iirc it’s been a while): we’d periodically dump all the translation strings from our translation editor app (MySQL backed) into a sparkey S3 path, and use a Kubernetes daemonset to fetch the sparkey file to each host in the cluster. Finally application pods written in any language use a host volume to read translation strings from the local sparkey file. Certainly overkill for smaller apps but with a bunch of services and hundreds of thousands of translation strings, the out of band updates are well worth it and keep the app container small.