I love this language but have never found a production use case for it, versus just using something less obscure like Go. It's the Ruby we wish we had in the 10s.
I write a lot of Go. It’s great. CGo is also good. But Crystal is even more easily interoperable with C libs and has a slimmer runtime. It’s also even faster in my real world testing. Down sides vs Go are compiler speed and general ecosystem is much smaller. But I’ve written several things in Crystal in prod and it has been very good.