I'm not the persuasive person that convince the bosses to use Scheme, so I don't have a triumphant success story, but some minor victories. I'm one of the core developers of GNU Guix (a package manager, distro, and associated set of tools) that recently was deployed successfully in a large production HPC cluster in Germany, which I think is a pretty nice achievement. At work, I use Guix and an init system called DMD (also written in Guile) a lot for development, and I'm trying to slowly work them into production via Docker.

It's an uphill battle to advocate for something that isn't the status quo, so I'm proud of the little victories.