React: Internals and Advanced Performance Patterns

Writing fluid user interfaces becomes increasingly challenging as the application complexity increases. Also, in a world with a wide variety of network connections, any user can have a slow experience, and apps that delight users on fast connections can barely be usable on slow ones.

With a methodology based primarily on:

Revisiting Computer Science concepts.

Understanding how tools work under the hood and the rationales behind that by checking their source code.

Leveraging real-world case studies from small, medium, and enterprise-scale companies.

In this workshop, we will address the following topics:

Scheduling, reconciliation, React Fiber, and concurrent React features.

Static analysis, compilers, the React compiler, and Million.js.

Different rendering patterns, like islands, streaming SSR, and React Server Components.

A wide range of native, performance-related, browser APIs.

Measuring responsiveness, and reliably identifying culprits for bad experiences.

Apply modern techniques to legacy codebases, via code generation, polyfilling, and others.

️Presentations

  • CityJS London 2025

    London, United Kingdom 🇬🇧