[100k]

I heard second hand that this really happened at Living Social. Engineers would write services in whatever they felt like (sorry, I mean, "the best tool for the job"), then get bored and leave.

Heck, this was even a fad for a while: polyglot programming.

[staticassertion]

Polyglot programming isn't "a fad" - it's something that microservices enable. That does not mean that developers make technical decisions in isolation.

If I were to introduce Haskell to my company there would have to be at least one other person interested in it and at least a few people who would be interested in learning it. I would never commit code using a new technology without discussing that with my manager.

[emperorcezar]

Polyglot isn't a fad. That's like saying, as a carpenter, using more than a hammer is a fad. As a professional, you are supposed to have more than a single tool. That doesn't mean you use all of them on every job, but you should have them.