Stefan Wehr is a professor at the Offenburg University of Applied Sciences. Before becoming a professor, Stefan worked in industry on a large Haskell codebase - specifically one that's not a compiler and not a blockchain. So of course we talked about using Haskell in large projects, software architecture, modularity, type classes and data modeling and the suppression of sums outside of functional programming, and also about teaching Haskell at his current job.