Vaadin 25.3 Migrates Browser Engine to TypeScript and Updates Observability

Vaadin 25.3 ships with an architectural shift in its browser-side engine and updates to observability tooling. The release moves observability away from the OpenTelemetry Java agent to Micrometer. In Spring Boot environments, you can now monitor UI-level performance data—including slow interactions and the specific views triggering individual JDBC queries—by adding a single dependency.

The internal browser-side engine transitions from GWT to TypeScript. This component now contains 107 TypeScript modules totaling about 19,000 lines of code, and it runs over 700 browser tests. Although the underlying engine underwent a fundamental rewrite, the Java APIs remain unchanged to preserve backward compatibility for existing applications. Vite provides source maps for the client-side code.

Testing workflows change to improve parity with end-user behavior. Browserless UI tests now enforce stricter rules. If a UI element like a button is hidden or disabled, the test runner prevents interaction with it. This makes automated tests more representative of actual user states.

You can check the official project platform for detailed release notes and technical documentation regarding these changes.