Hey, I'm Stefan. I develop digital services and products.

Frontend nerd, organizer of the Web Performance Group Berlin, occasional teacher, curator of Perf Tooling Today, organizer of CSSclasses Berlin and Developer Evangelist at Contentful.

I also read a lot of newsletters and listen to a few podcasts, document my web dev learnings constantly and write a monthly newsletter.



  • Frontend development 2018 – what's in your stack?

  • AOM (Accessibility Object Model) – really quick!

  • What the v...DOM?

Developer Smalltalk

  • Using Cypress for end-to-end testing with Gleb Bahmutov

  • Using ES modules in Node.js today using @std/esm with John-David Dalton

  • Setting up Sitespeed in AWS with Peter Hedenskog

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