qgis-js brings the QGIS core rendering engine to the browser via WebAssembly — no server-side map rendering required. Since its initial release, the project has matured significantly: all qgis-js patches have been upstreamed into QGIS core, and wasm32-emscripten is now an officially supported build target. This means new qgis-js versions can be built directly alongside QGIS releases, with CI ensuring ongoing compatibility.

In this talk, we will cover the recent project developments — what has changed, what new capabilities are available, and where the remaining challenges lie — before diving into a real-world application: a browser-based cockpit built for the Swiss Federal Office for the Environment (BAFU) as part of their modular warning system SAM. The application supports early warning decisions for spontaneous landslides and debris flows by presenting complex model results — precipitation thresholds, exceedance probabilities, and time series — as interactive, QGIS-styled maps and diagrams directly in the browser. What started as a QGIS desktop prototype with project macros and attribute form plots is now a highly interactive web application powered by qgis-js, accessible to warning officers without any software installation.

We will share the architectural decisions behind the application, the lessons learned integrating qgis-js into a production web app, and our outlook for the project's future.