Mercury, a fintech company serving over 300,000 businesses, operates approximately 2 million lines of Haskell code in production with a largely generalist engineering team, processing $248 billion in transaction volume in 2025. The company's success with Haskell at scale stems from prioritizing adaptive capacity and system reliability through graceful degradation, clear APIs, and compiler-enforced safety rather than focusing solely on preventing failures.
Otto Beta
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Mercury, a fintech company serving over 300,000 businesses, operates approximately 2 million lines of Haskell code in production with a largely generalist engineering team, processing $248 billion in transaction volume in 2025. The company's success with Haskell at scale stems from prioritizing adaptive capacity and system reliability through graceful degradation, clear APIs, and compiler-enforced safety rather than focusing solely on preventing failures.