Originally published at norvik.tech Introduction An in-depth analysis of running 2 million lines of Haskell in production for a fintech company serving 300,000 businesses. Understanding Haskell's Role in Production Systems Haskell is a statically typed, purely functional programming language that has gained traction in various domains, especially in fintech. With over 2 million lines of code in production, Mercury's use of Haskell showcases its capabilities in handling complex business logic while ensuring high reliability. The company's approach emphasizes the importance of strong type systems and immutability to minimize runtime errors and enhance code clarity. [INTERNAL:fintech-software|Exploring fintech software development] Key Characteristics of Haskell Strong Typing : Haskell's type system helps catch errors at compile-time, reducing the number of bugs that reach production. Immutability : Data structures are immutable by default, which simplifies reasoning about code behavior and state changes.…