In my work at MTN Irancell, we are building a Camunda-based workflow platform on top of bpmn-io Form-JS, a form engine that is rendered in Preact. The first time I had to bring a React component inside that Preact tree, it took me 2 weeks. I faced the famous "h is undefined" error one hundred times, two copies of React in memory, hooks failing, and re-render fights between Preact and React owning the same DOM. In this talk I will show the bridge I designed to solve all of this in production, with a live demo on stage where I mount a React component inside a Preact form engine in front of you.
This talk has been presented at React Day Berlin 2026, check out the latest edition of this React Conference.





















