Responsiveness to user interaction is crucial for modern web apps, and we’ve all heard about many fantastic tools for measuring and optimizing performance.

However, we no longer have to rely entirely on pre-built dashboards to understand performance. Browsers already expose a rich set of native performance APIs that let us go deeper.

In this talk, we’ll explore lesser-known platform primitives for measuring responsiveness and diagnosing bottlenecks. From observers and timing APIs to scheduling primitives and resource hints, through navigation improvements like View Transitions.

Be ready to turn your browser into a performance toolkit and build performance metrics that reflect what your users really care about.