I am a Freelance Software Engineer with an interest in interactive, dynamic, self-sustaining programming tools and authoring environments.

In the past I've worked for Google, Y Combinator Research, and at the HPI Software Architecture Group. I have created the lively.next runtime and development environment, a successor to the Lively Kernel project originally created by Dan Ingalls. For more details see my résumé.

You can find me online on Github and Twitter.



I provide services around application and web development including:

  • Project assessment: Finding and reviewing architecture and design decisions that enable scalability and maintainability of software projects large and small.
  • Design, prototype and implement software systems using an agile approach iterating quickly and offering short feedback cycles. I work remote and on-site.
  • Teach and mentor the usage of programming languages and frameworks either in person or via video courses I produce.

The technology stacks I focus on are Clojure/ClojureScript, JavaScript/TypeScript, and Rust/C++/C.

My experience includes successfully implementing rich frontend applications, scalable servers and data processing / backend systems. I have worked for a number of early stage startups as well as large established enterprises.

Furthermore I continue to be especially interested in development tools and are actively engaged in improving the tooling ecosystem for Clojure and ClojureScript.

Do you have a project I might be able to help with? Please get in touch!

Posts feed-icon-14x14.png

[2019-11-29 Fri] Clojure Conj 2019

[2019-11-28 Thu] Scraping Patreon Feeds

[2019-08-13 Tue] Org Analyzer

[2019-06-20 Thu] Developer Efficiency


suitable — "IntelliSense" using runtime inspection to aid exploratory development in ClojureScript.

lively.next — The latest version of Lively

BrightTable — A GUI for the real world

Draggable Code — Tile scripting & programming by example

JavaScript (back-in-time) debugger — A debugger implemented in pure JS

cloxp — A Clojure IDE for live programming

paredit.js — A library for parsing & navigating Lisp expressions. Used in Atom and other IDEs.

CodeChisel3D — Live programming in 3D / VR

Lively Web — Lively 2009-2016

Selected Publications

A World of Active Objects for Work and Play: The First Ten Years of Lively (Daniel Ingalls, Tim Felgentreff, Robert Hirschfeld, Robert Krahn, Jens Lincke, Marko Röder, Antero Taivalsaari, and Tommi Mikkonen. OOPSLA/Onward! 2016)

The Lively PartsBin: A Cloud-based Repository for Collaborative Development of Active Web Content (Jens Lincke, Robert Krahn, Dan Ingalls, Marko Röder, and Robert Hirschfeld. HICSS 2012)

Lively Wiki - A Development Environment for Creating and Sharing Active Web Content (Robert Krahn, Dan Ingalls, Robert Hirschfeld, Jens Lincke, and Krzysztof Palacz. OOPSLA/WikiSym 2009)

Lively Fabrik - A Web-based End-user Programming Environment (Jens Lincke, Robert Krahn, Dan Ingalls, and Robert Hirschfeld. C5 2009)