[virtualwhys]

You mean the guy that one could argue is solely responsible for the Code of Conduct header on every TypeSafe affiliated Google Group?

Yah, that guy. Sure, for $250/hour he's probably fairly amicable.

He's categorically brilliant (in FP implemented Scala, certainly), but good luck grokking his mile long type signatures when he's gone from the project.

Saying that, if part of his consultancy is to train the team in FP and explain his code, then there is "real" value in the hiring; otherwise, where would you know to begin when updating the system down the road?