In my experience at work, the business has problems and asks the technical teams for solutions. The technical team consists of just people, of course, and thos

In my experience at work, the business has problems and asks the technical teams for solutions. The technical team consists of just people, of course, and those people identify what the available options are for the solution. The more capabilities our team has, the more options we have to pick from. What I'm saying is instead of trying to pick a language (Lisp, Haskell, etc) to get good at to land a job that currently requires it, you should instead pick one that you enjoy learning and pursue it doggedly. This puts you in the position of recognizing the types of problems well suited to that solution. Inevitably, the business will raise a problem and you can demonstrate that a functional language solves it and you're suddenly working in the language you wanted. Of course, constraints vary from team to team and company to company. I think it would be harder to introduce a new language to a large, highly regulated company than a start up. In that case, your consideration should be less about which language to learn and more about which company to apply to.