Are there any companies using Julia at the moment? This isn’t a snarky comment - I’m genuinely interested in hearing who’s using them, as well as reading any associated blogs etc.

You can see some examples here: https://juliacomputing.com/case-studies/

Additionally, a lot of use cases were discussed at the recent JuliaCon (and in years past): https://www.youtube.com/user/JuliaLanguage/videos

There are a lot of backend data science applications using Julia. I was involved in a 3D printing startup and we developed a path planner beginning with Julia 0.3. You generally have to precompile your dependencies into the base library, but once this is all containerized things run great (pretty much as fast as C++ in our case with a little bit of JIT overhead in the cornercases), and you just have to create some sort of API for the service. For backend, long-running, services it is a great language now. The client-side application/static compilation story is massively improving and is fortunately mostly possible outside of the core languages development. E.g. the infrastructure is there in the core language for static compilation, but the interfaces are still developing.

Do you have a guide on how to compile packages into base image?

There is also now PackageCompiler that provides a nicer API without requiring you to build from source: https://github.com/JuliaLang/PackageCompiler.jl