Perhaps it's a borderline case, but I've used Julia to make a "big data" database server, backed by a mmap'ed column store. Because the compiler's available at

Perhaps it's a borderline case, but I've used Julia to make a "big data" database server, backed by a mmap'ed column store. Because the compiler's available at run-time, queries can be compiled into efficient kernels that can run in parallel over multi-gigabyte arrays orders of magnitude faster than MySQL or Postgres on the same hardware. Without Julia, I would have had to find some other way to compile queries into machine code at run-time, which for me would have ruled out all the languages you listed. In practical terms I would have abandoned the project.