Several large financial firms have significant Haskell codebases, plenty of random cryptocurrency startups are Haskell based, some of the Google TPU chips are/were written in Haskell/Clash, Facebook has a big Haskell codebase, Starbucks and Target use it, there are several national security/defense firms extensively using Haskell, etc. etc.

Just because you don't see a bunch of blog posts like "We rewrote our <useless product> in <language du jour>!" doesn't mean it's not being used. In fact, more serious companies tend to lean less heavily on the developer social media publicity circuit.

> Starbucks and ... use it

I have heard of Haskell used in companies mentioned by other comments, but I am surprised, pleasantly, that Starbucks uses Haskell.

Do you have a pointer (job posting, blog post, etc.) to Starbucks using Haskell? It could help me push for using Haskell by my employer, for example.

Facebook's spam filtering: https://engineering.fb.com/2015/06/26/security/fighting-spam...

They also occasionally contribute libraries like Haxl [0] and HsThrift [1]

[0] https://hackage.haskell.org/package/haxl

[1] https://engineering.fb.com/2021/02/05/open-source/hsthrift/

Shellcheck - https://www.shellcheck.net/ PostgREST - https://postgrest.org/en/v7.0.0/ Semantic - https://github.com/github/semantic Pandoc - https://pandoc.org/

Starbucks uses a system with a Haskell frontend and backend for generating their personalized offers. I have it on good authority that it's probably been responsible for more than a billion dollars in revenue lift for Starbucks.

This is new to me.

I have heard of Haskell used in companies mentioned by other comments, but I am surprised, pleasantly, that Starbucks uses Haskell.

Do you have a pointer (job posting, blog post, etc.) to Starbucks using Haskell? It could help me push for using Haskell by my employer, for example.

Starbucks themselves didn't use Haskell. They used a system built by another company that used Haskell.

Depends your definition of "significance" but Cardano is written in Haskell, and its main smart contract language is also Haskell.

https://cardano.org/

CircuitHub is apparently built with Haskell. It's the most polished PCB manufacturing quote system I've seen, but "significance" is relevant. (Plus I've never actually used their service, since it's not priced for hobbyist manufacture of a small number of boards).

Pandoc comes to mind.

It might help if you define "of significance".