8 months of OCaml after 8 years of Haskell in production

A senior Haskell practitioner published an experience report after eight months using OCaml professionally at Bloomberg, contrasting it with eight prior years of Haskell. The author cited OCaml's "ergonomic mutability" and simpler, extension-free semantics as primary productivity benefits, reducing cognitive load compared to complex Haskell type errors involving features like MultiParamTypeClasses. Community discussion validated OCaml's practical toolchain, with PPX preprocessors providing derive-like functionality and Jane Street's sustained investment credited for ecosystem growth. The blog post was subsequently updated based on community feedback, refining library recommendations and acknowledging OCaml's own error message quirks. Concrete outcomes included the author’s public shift in primary language focus and a detailed comparison table that sparked broader debate on language design trade-offs, specifically the stability versus innovation balance. The discussion served as a visible marker of ongoing developer migration between these ML-family languages, driven by perceptions of industrial maintainability.