I've been building an app on crystal and really enjoy it but have noticed some of the growing pains as it ramps up to 1.0.

Its great but may not quite be ready for production unless you don't mind fixing the occasional breaking changes. Its supposed to hit 1.0 this year.

But Crystal doesn't run on BEAM, which (I assume!) is something OP was looking for.

Right, but my post was in response to the one above about how we don't need another dynamic language because a statically typed language like Go is so much better at catching errors. Even though you have to write more code while being restricted in what can be expressed. Thus, Crystal makes sense, best of both worlds, and what not.

Of course if you're looking for functional on Beam, then neither Go or Crystal are good comparisons.

Yes, Crystal's type inference looks really promising. I hope it will gain enough momentum.