

The Haskell Interlude
Haskell Podcast
This is the Haskell Interlude, where the five co-hosts (Wouter Swierstra, Andres Löh, Alejandro Serrano, Niki Vazou, and Joachim Breitner) chat with Haskell guests!
Episodes
Mentioned books

Mar 22, 2026 • 1h 7min
79: Peter Thiemann
Peter is a professor at the University of Freiburg, and he was doing functional programming right when Haskell got started. So naturally we asked him about the early days of Haskell, and how from the start Peter pushed the envelope on what you could do with the type system and specifically with the type classes, from early web programming to program generation to session types. Come with us on a trip down memory lane!

Mar 8, 2026 • 43min
78: Jamie Willis
In this episode, we focus on a particular part of Haskell: teaching it. To help us, we are joined by Jamie Willis who is a Teaching Fellow at Imperial College London. The episode explores the benefits of live coding, and why Haskell is the best language for teaching programming.

Feb 22, 2026 • 58min
77: Franz Thoma
Franz Thoma is Principal Consultant at TNG Technology Consulting, and an organizer of MuniHac. Franz sees functional programming and Haskell as a tool for thinking about software, even if the project is not written in Haskell. We had a far-reaching conversation about the differences between functional and object-oriented programming and their languages, software architecture, and Haskell adoption in industry.

Jan 25, 2026 • 1h 4min
76: Jeffrey Young
Welcome to the Haskell Interlude. Today, Matti and Mike talk toJeffrey Young. Jeff has had a long history of working with Haskell andon ghc itself. We talk about what makes Haskell so compelling, thegood and bad of highly optimized code and the beauty ofwell-modularized code, how to get into compiler development, and howto benefit from Domain-Driven Design.Jeff is currently on the job market - if you want to get in touch,email him at mailto:jmy6342@gmail.com.

Jan 11, 2026 • 51min
75: Kathrin Stark
We are joined by Kathrin Stark, a professor at Heriot-Watt University in Edinburgh. Kathrin works on program verification with proof assistants, so her focus is not exactly on Haskell, but on topics dear to Haskellers' hearts such as interactive theorem provers, writing correct programs, and the activities needed to produce them. We discuss many aspects of proofs and specifications, and the languages involved in the process, as well as verifying and producing provably correct neural networks.

Dec 19, 2025 • 1h 21min
74: Lennart Augustsson
This episode is a deep dive into the evolution of Haskell and functional programming with one of its pioneers, Lennart Augustson. It reflects on decades of work in language design and compiler implementation. Lennart speaks about his early involvement in the creation of Haskell, shares thoughts on type systems, performance, and the balance between purity and practicality. The conversation ranges from personal history to big-picture views on the evolution of programming languages, with plenty of insight into what makes Haskell both powerful and challenging. A rare opportunity to hear from one of the foundational voices in the functional programming world.

Nov 13, 2025 • 38min
73: Jean-Philippe Bernardy
In this Interlude, we’re joined by Jean-Philipe Bernardy, a Senior Lecturer at University of Gothenburg and Chalmers University of Technology. We discuss letting types be your guide, getting into AI to feed yourself, and never testing your programs.

Oct 30, 2025 • 57min
72: Manuel Chakravarty
In this episode, we talk to Manuel Chakravarty - specifically, his work on the ghc backend such as data-parallel Haskell and the FFI and how that work segued into type system design. We also discussed Manuel's perspective on Haskell from the language design of Swift.

Oct 16, 2025 • 50min
71: Stefan Wehr
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.

Sep 14, 2025 • 1h 2min
70: Phil Wadler
We sat down with Phil Wadler, one of the most influential folks in the Haskell community, functional programming, and programming languages, responsible for type classes, monads, and much more. We take a stroll down memory lane, starting from Haskell's inception. We talked about the difference between research and Phil's work on impactful industrial projects and standards - specifically XML and the design of generics in Java, as well as Phll's teaching at the University of Edinburgh using Agda.. Phil is a fountain of great ideas and stories, and this conversation could have gone on for hours. As it is, we hope you enjoy the hour that we had as much as we did.


