Formerly of Microsoft Research,[2] Marlow has worked at Facebook between March 2013 and early 2025. The "noted Haskell guru"[3] is part of the team behind Facebook's open source Haxl project,[4][5] a Haskelllibrary that simplifies access to remote data,[6] and later "Glean".,[7] a "system for collecting, deriving and querying facts about code".