[liampulles]

Unless the main set of languages you have are totally unable to solve the new usecase, its almost certainly going to land on the tech debt side of things. This is a new build chain, set of dependencies, development tools, developer skillset, etc. we are talking about here - not small stuff.

Also to get common libs (e.g. middleware, API definitions) going will be much harder.

The real reason new languages come up in discussion is because of bored developers - that has been my experience at least. And I don't exclude myself from that, it is a major factor in me looking for new work. Now assuming that cynical theory is true, there is an argument to introduce cool stuff to retain good developers - with the understanding that you are shooting yourself in the foot a little bit.

I've wondered about the possibility of allowing a prototype in a "cool" language or framework, with an understanding that it must be replaced soon after by a stable refactor in the existing language set. I think that would appeal to people who want to try something new as well as people who enjoy refactoring, and there would be a kind of extreme programming motivation to the business. I've never tried to get this kind of thing going though.

[simonw]

I've worked at several companies that have used Hack Days as that release valve, which has worked really well.

Once or twice a year have a 2-3 day break where engineers can build prototypes using any technology they like. Ideas that look good can get turned into production projects, sometimes (but not always) rewritten in a supported stack.