Our shop converted 6 years ago, from C# to exclusively F#. I also author and maintain some packages (falco, donald, validus and others). The language is tough to learn if you're coming from a C-style language. But worth the effort and experience. It's extremely concise a true delight to build programs in that are fast, robust and durable.

There are a few drawbacks, depending on your perspective:

- compilation is slower than c# and hot reload isn't supported (it's in progress)

- there are very few opportunities to use it professionally

- hiring devs can be challenging

Hiring devs is perfectly fine if you don't look for F# skills - just hire generally smart people, and allow them 1-2 weeks to get comfortable with F#. Make them just solve problems from project euler or something.

For those who have already done functional programming, they wont take more than 2 days to start getting productive. For those who have written a lot of code, it will take them ~2 weeks to pick up functional thinking.

Anyone who is still uncomfortable with F# after 1 month - well that's a strong signal that the dev isn't a fast learner.

Additionally, I've never had anyone reject our job offer because we do F#. I'm sure a whole bunch of people might only be looking for python or javascript jobs, but that's fine because I'm not looking for them. I always have more people who I want to hire but I can't due to budget constraints.

Source: direct experience - I run a pure F# company with a team size of ~80.

As a proficient Elm developer with industry experience, I’m wondering what are the biggest challenges in hiring devs? Is it the paradigm, learning the ecosystem, lack of interest? Are you currently hiring?

How does the typing system work for F#?

From the article, it looks like it's mostly dynamically typed. Or is it inferred? Or is it something else?

Like, if I write

    let hello value =
      print value
    
    hello "world"
    hello 2

To me, that'd be a point that might steer me away from the language. Deducible types seem vital to larger and long lived projects.

>- there are very few opportunities to use it professionally

- hiring devs can be challenging

Those drawbacks are huge, IMO.

Thanks for your work on falco, it’s a really great library.