From business point of view it might be a good solution to stick to only one language in stack.

What's wrong with that?

String work in C for starters. Commonly accepted best practice is to use the least powerful language for any given problem. This is so it's (a) readable (b) portable (c) nominally secure (d) preserving of programmer time.

While there are exceptions, their reasons are questionable at best. It seems more like a declaration of a cultish C culture. Which, in context, is probably attractive to some of the people they're looking for, but hideously backward by general standards. Use the right tool for the job.

Yesh...