I've been using it in production (Deno) for a while. It's pretty solid, but their documentation is sorely lacking, so you often have to feel your way to getting more complex things to work.
Could you comment on what you're using deno in prod for? I'm curious to see and learn more about deno for production cases. I'm a big ts and nodejs user, and deno always seemed interesting to me. However I am afraid of being an early mover, so I like to learn more about use cases people have validated.
We use it for processing real-time UDP streams, as well as storing the data in postgres (as well as a hosting small API for exporting said data). We also use it to re-publish the UDP streams in a WebSocket format, for consumption by web applications.