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Some companies use Haskell to execute complex and atypical tasks in different spheres like security, fintech, hardware backend, blockchain, big data, etc. Facebook engineers have chosen Haskell for its performance, interactive development support and other features that make Haskell the best choice for their Sigma project. Microsoft uses Haskell in its Bond project for working with schematized data. Facebook uses Haskell to fight spam. IBM, AT&T, and Bank of America also use Haskell and functional programming solutions for their projects.