“Equipping an existing programming language with a gradual type system requires two major steps. The first and most visible one in academia is to add a notation for types and a type checking apparatus. The second, highly practical one is to provide a type veneer for the large number of existing untyped libraries. … When programmers create such typed veneers for libraries, they make mistakes that persist and cause trouble. … This paper provides a first, surprising answer to this [dilemma] via a rational-programmer investigation.”

Find the paper and full list of authors in the proceedings of the ACM on Programming Languages.