[seagreen]

  I remember showing a new engineer who'd never seen
  any Haskell before monads on a whiteboard and he
  after I explained monoids and functors and then monads,
  he just nodded and said "oh, okay, makes sense".
  He wasn't bluffing - he actually internalized the concept
  that quickly.

This is amazing.

  The trick with teaching Haskell is to start with specifics
  and THEN generalize the ideas.

Definitely!

  Sorry, I rambled a bit, but tl;dr: Haskell was a mixed
  success, brought along some drama, but overall enabled
  us to reduce the latency of some critical services by
  about 10x. At least while I was at IMVU, teaching people
  Haskell was actually not hard. Getting them to care
  about Haskell or even want to try it was sometimes VERY
  hard, depending on the person.

Please, please, PLEASE turn this into a blog post. Haskell has a lot of great testimonials, but they can't be convincing unless they also show the downsides. For technical topics I think Haskellers do a great job being honest, eg: https://github.com/Gabriel439/post-rfc/blob/master/sotu.md ("Numerical -- immature ... Front End ... immature ... Distributed programming ... immature"). But there aren't a lot of writeups of Haskell being tried in business with mixed results. A writeup saying "a big concern is getting developers onboard" would be hugely reassuring to companies considering Haskell that _do_ have their developers onboard.

  Oh yeah, and I 100% agree with slezakattack that Haskell
  programmers are not necessarily magical systems designers
  or system programmers. They're just like you and me.

Totally. There are some geniuses, but then there are also people like me who use it because my brain isn't big enough to hold a whole program in my head, so I need the types:)

[chadaustin]

Your comment inspired me to write it up, so thanks for that. :)