I've been playing with it for about 5 years, started the local Haskell meetup, etc. I used it on a side project that reached beta in 2015, and on a startup at the beginning of 2016. Starting at the end of 2016 I started using it on a big contract. I had to convince the client it was a good idea, but they've been convinced by my team's productivity. All of the above were back end web services. The current project is a bunch of systems to underwrite and issue loans and involves an ML calculation (hosted on data robot).
I love it for general back end web development. I can actually solve problems so they stay solved.
I'm VERY curious about this! Backend web services not being the sexiest / most theory-requiring subject.
How did you convince the client, and why did you choose Haskell for this over, say, .NET, which throws a web service up quicker than it took me to type this? What sort of productivity are you achieving?
I love it for general back end web development. I can actually solve problems so they stay solved.