Struggling with JavaScript performance in React Native?

In this webinar recording, Callstack's CTO Mike Grabowski and Software Engineer Szymon Chmal take you through Part 1 of the 2025 Ultimate Guide to React Native Optimization, focusing entirely on JavaScript performance.

If you’ve dealt with dropped frames, laggy interactions, or choppy UI updates, this session is for you. Get a behind-the-scenes look at the latest optimization strategies, watch practical techniques in action (with real code examples), and hear clear answers to some of the toughest performance questions facing React Native developers today.

What you’ll learn about JavaScript performance optimization

• How to use the right tools to identify true JavaScript and React bottlenecks.
• Why incorrect usage of Context API leads to unnecessary re-renders, and how to fix it with smart memoization.
• How non-memoized ^renderItem functions and improper configuration can tank performance in the case of FlatLists—and what to do instead.
• How synchronous work (like frequent ^{Intl.DateTimeFormat} creation) can block the JS thread, and how to avoid it.
• How to handle heavy computations without freezing the UI using techniques like yielding.

Why you can’t miss it

Callstack’s Ultimate Guide to React Native Optimization is a go-to industry reference. The 2025 edition reflects the biggest changes in performance strategy, and this webinar gives you early access to the insights, straight from the people who wrote the guide.

This recording includes an interactive walkthrough and Q&A session.

By the end of this session recording, you’ll have:

• A deeper understanding of JavaScript performance tuning in React Native.
• Real techniques you can apply immediately.
• Answers to performance questions, directly from the authors of the guide.