Published March 7th, 2024
Earlier this week, Bleacher Report was bought out and forced to re-write their Elixir/Erlang backend in something "more-mainstream" by the buying party (Warner), this is a HUGE mistake, and an example of how main-stream thought has eroded the foundations of software engineering. Bleacher Report had used Elixir/Erlang since at least 2017, when their case-study of going from 150 servers to 5 via converting their Ruby code to Elixir/Erlang was published. All of this resliency, and engineering effort is now going to be rewritten in none other than JavaScript, which of course will be a tremedous effort.
So why did they do it? Well, they had lay-offs, and then they needed to re-fill the seats they laid off a few years later. Instead of leveraging this "gold card" that is a niche language, Warner decides that it will be too hard to fill N seats. Which is also another issue in the software world, the "butts in seats typing" phalacy that more will get done. Anyways, what Warner could have done, is use this fantastical power bestowed by a niche language, and got the best developers in that niche technology. If they hired 15 Node devs for 100k a year each, they could afford 5 Erlang masterminds for 300k a year each (and then you wouldn't need a rewrite!) The other option is to hire a few Erlang devs and have them train other devs which could be an effective cost-cutting measure as well, without having to rewrite your codebase.
I've been asked many times by developers, "should I learn X, it's so niche but it looks cool", and to every single one of those questions, I shout "YES!!!". Learning is ALWAYS good. But also, if you get really good at these niche technologies, you can become a SME (subject matter expert), and get hired by a business looking for people like you. Jane Street is notorious for using OCaml for literally everything. Yaron Minsky, mentions at Jane Street states that while there aren't many OCaml developers, the small set that does exist is typically really good, and a grade above the usual Python, Java, JavaScript developer (you'll choke on your coffee when you read Jane Streets developer salaries as well).
When starting a new project I think you should consider using a niche language. You learn a lot, but also when it comes time to scale your idea, and you need to hire a partner or two, you'll be greatful you chose it, when extremely talented and passionate individuals send you their resume solely because you chose a backend written in Haskell, Scala, Perl, OCaml, Elixir, Clojure, Lua, etc. This is what happened for NoRedInk, after writing their original MVP in Ruby, they ended up using Haskell and Elm for new services, and now, they're one of the most well known Functional Programming shops, and they've managed to hire some brilliant people, like the creator of Elm himself!