Working with Haskell professionally sounds like a very interesting career path. Could you point to some resources to get better at the production Haskell skills that these companies are looking for? Perhaps gaining experience with projects which use Haskell in a similar way to the companies you mention could help with finding that first Haskell job.
I'm not sure what your current level is, but I can give some general advice for people that happen upon this:
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Haskellers are generally expected to understand most of the typeclassopedia (https://wiki.haskell.org/Typeclassopedia), don't worry about learning it all in one go. I had to read this page many times before I grokked most of it.
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Avoid tutorials that overuse analogies. A Monad only adds one operation to Applicative:
class Monad m where
(>>=) :: m a -> (a -> m b) -> m b
This reads as: `m` is a monad if, given an `m a`, and an `a -> m b`, you can construct an `m b`.
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It's important to be really good at using Monads that support multiple effects, to create little DSLs. If I want a component of my program to support throwing errors, creating a log, and reading an environment, (all purely), I'd use something like this:
type MyDSL
= ReaderT Environment
(WriterT [String]
(Except ErrorType))
These are monad transformers from the mtl library.
Where I work we use free monads instead of monad transformers, but that's just an implementation detail, it's used the same as a transformer stack.
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Create a cool project, Haskell people like languages. When I was interviewing I showed off a tiny lisp-like language implemented in Haskell (https://github.com/414owen/phage). This was my first non-trivial Haskell project so don't judge it too harshly.
