Rethinking Performance Engineering Around INP, Responsiveness, and User Perceived Speed

This session looked at how frontend performance work is changing as engineering teams move beyond load speed alone and focus more directly on responsiveness and user perceived quality. The talk explored how modern products are evaluated through interaction quality, not only initial rendering.

The discussion covered interaction latency, rendering bottlenecks, main thread pressure, scheduling decisions, and the engineering choices that improve responsiveness across complex interfaces. It also addressed how performance teams can align technical metrics more closely with what users actually experience.

The session showed why performance engineering now requires a broader view of product behaviour, interface design, and runtime decision making across the full lifecycle of the application.

This talk covered

• Responsiveness as a core performance concern
• Interaction delays and runtime bottlenecks
• Rendering cost and scheduling trade offs
• User perceived speed in complex applications
• Performance measurement beyond initial load