Dawid Matyjasik
Software Engineer @Software Mansion
I am a Software Engineer at Software Mansion with over six years of experience, acting as a go-to expert for React Native performance and the New Architecture. I specialize in solving complex bottlenecks, and most of my day-to-day work is dedicated to helping large-scale commercial clients optimize, stabilize, and scale applications that handle millions of active users under heavy load.
Beyond my core work and past contributions to the open-source ecosystem, I am deeply involved in the developer community. Recently, I run performance workshops at App.js Conf 2026 alongside my coworkers. I am also a regular participant at major industry conferences, including React Universe 2025 and previous editions of App.js. Whether I am mentoring developers at local hackathons, exploring emerging tech at AI meet-ups, or joining discussions at Cursor Cafe, I am passionate about sharing knowledge and connecting with the tech community.
React Native: Performance Analysis & Optimization
Handling massive, heavy lists in React Native is a notorious bottleneck when applications scale to enterprise levels. But before fixing code, you must know how to measure it.
Driven by the exact engineering patterns we use at Software Mansion for large-scale products, this hands-on workshop teaches you how to diagnose and optimize list performance at scale. We will start by mastering tools like Flashlight, the React Native Performance devtools panel and the Profiler to pinpoint the root causes of UI lag. Once we isolate the bottlenecks, we will take a heavy, unoptimized application and rewrite its list architecture together.
Key Takeaways:
- Using Flashlight and DevTools to find the exact root cause of stuttering instead of guessing.
- Choosing between FlatList, FlashList, or Legend List based on memory constraints at scale
- Fine-tuning component recycling and cell layout stability to prevent layout shifts during fast scrolls and junks.