Andres Löh
Partner at Well-Typed LLP
Regensburg, Bavaria, Germany
Summary
🤩
Rockstar🎓
Top SchoolAndres Löh is a Haskell-focused programming languages engineer and partner at Well-Typed with over 21 years in software, including more than two decades of Haskell development and 15+ years of teaching. He specializes in datatype-generic programming, type systems, dependent types and embedded DSLs, combining research rigor (PhD from Utrecht) with pragmatic consulting and training. His open-source work spans flagship Haskell projects—he added UHC support to Cabal, refined the LiquidHaskell parser and helped optimize Servant’s server routing—demonstrating both tooling and type-checker expertise. He founded the Dutch Haskell Users Group and started an applied functional programming summer school, reflecting a long-standing commitment to community-building and education. Based in Regensburg, Germany, he turns deep theory into practical improvements that make code more modular, robust and reusable.
21 years of coding experience
3 years of employment as a software developer
Diplom, Mathematics, Computer Science, Diplom, Mathematics, Computer Science at University of KonstanzPhD, Computer Science, PhD, Computer Science at Utrecht University
German, English, Dutch
Github Skills (24)
api-rest10
parser10
nix10
package-management10
api-design10
restful-api10
build-system10
cabal10
rest-api10
haskell10
routingslip9
dependency-management9
routing-slip9
verification9
type-systems9
Programming languages (13)
Github contributions (5)
haskell/cabal
Nov 2005 - Oct 2016
Official upstream development repository for Cabal and cabal-install
Role in this project:
Back-end Developer
Back-end DeveloperContributions:342 commits, 16 PRs, 14 pushes in 11 years
Contributions summary:Andres contributed significantly to the Cabal project, focusing on enhancing the build process and supporting additional compilers such as UHC. Their work includes implementing new functions within the build information structure, and addressing bugs related to file paths and dependency handling within different compiler backends. The user also added a new module for UHC compiler support, which included building, configuring, installing, and registering package features within the cabal-install environment.
hackagecabalhaskellupstream
haskell-servant/servant
May 2015 - Jan 2017
Servant is a Haskell DSL for describing, serving, querying, mocking, documenting web applications and more!
Role in this project:Back-end Developer
Back-end DeveloperContributions:23 commits, 12 PRs, 14 pushes in 1 year 7 months
Contributions summary:Andres made significant contributions to the `servant` library, focusing on enhancing its server-side implementation. They introduced a new `Router` datatype for more efficient server interpretation, reducing routing complexity. The user also addressed error handling, test cases, and the implementation of API combinators such as authorization. The changes demonstrate a deep understanding of Haskell and web application server design principles.
web-applicationsservingqueryinghaskelldsl
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