I work on an internal analytics framework at Twitter. Twitter doesn't use Haskell. The most Haskell I've done there is to write an internal tool in Haskell (A

I work on an internal analytics framework at Twitter. Twitter doesn't use Haskell. The most Haskell I've done there is to write an internal tool in Haskell (A shell-based interface to HDFS). Everybody here knows that it's my mission to introduce Haskell more at Twitter and I have two long plays to do so (Morte is part of one of them). You would think that it would be easier to introduce Haskell at a Scala-based company because of the strong similarities between the functional half of Scala and Haskell, but it's actually quite the opposite: the marginal benefit of switching to Haskell is smaller so it's harder to make the case to adopt Haskell. This is why you see Haskell take hold more easily in companies programming primarily in languages far-removed from Haskell (like PHP or Python) because then the marginal benefit of switching is much higher.