We've shipped something simple and non-mission-critical in production (URL rewriting for ad placements).

It has been pretty much set-and-forget. Last anyone had to even look at it was almost 3 years ago, and afaik it's still working (our ad sales team would be complaining loudly if it weren't).

For something peripheral like that, it's nice not to have to run servers for it or devote any energy to keeping it running.

In terms of both server costs and upkeep costs, the economics have been highly favorable.

I'm not sure I'd use it yet for something mission-critical or that shipped changes frequently. My recollection is that when we did have to adjust it, debugging was a bear. Tho tooling for that may have improved in the last 30 months.