In 2015, Meta (formerly Facebook) utilized Haskell to combat spam within its various services. Haskell, a functional programming language, offered advantages such as strong type safety and a high level of abstraction, making it suitable for complex data manipulation tasks involved in spam detection. The integration of Haskell allowed Meta to enhance its spam filtering algorithms, improving response times and accuracy. As of now, there are questions about Haskell's current usage at Meta, reflecting ongoing curiosity about the tech stack used by major tech companies and the longevity of programming languages in production environments.