Notes on shipping better apps, faster.
React Native performance notes, architecture writeups, and field reports from the teams building Margelo products and open-source libraries.
The Go-To Guide for Understanding Keyboards in React Native (Part 1)
A deep dive into keyboard handling in React Native - from platform quirks to frame-perfect animations, and the techniques that make apps feel truly native.
Kirill Zyusko
How Margelo Helped Discord Improve React Native's New Architecture Performance
A deep dive into Reanimated internals, Fabric's Shadow Tree, and the fix behind Discord's android performance recovery.
Hanno Gödecke
What's New in VisionCamera V5?
VisionCamera V5 is a major upgrade for React Native camera apps: Nitro, a new Constraints API, in-memory photos, depth streaming, RAW capture, multi-cam, and modular plugins.
Marc Rousavy
Latest
Practical notes for teams building serious React Native apps.
Scanning Barcodes in React Native Apps: The Complete Guide (2026)
Every major way to scan QR codes and barcodes - from free to paid solutions - in React Native in 2026, compared by the creator of VisionCamera.
Marc Rousavy
Fitting RAG in Your Pocket: Local Retrieval in React Native
Build a complete Retrieval-Augmented Generation pipeline that never leaves the phone: local embeddings, native vector search with nitro-sqlite + sqlite-vec, and local generation using React Native.
Ritesh Shukla
Building a Real-Time Face Recognition App in React Native with VisionCamera
Face recognition on a phone is a relay race of small models, where detection, tracking, alignment, liveness, and embedding all finish in milliseconds without a face ever leaving the device. This guide walks the full pipeline in React Native with VisionCamera, with real benchmark numbers and the production traps we hit building it.
Patrick Kabwe
Building a ChatGPT-Style AI Chat App in React Native with RAG & Streaming
A native-feeling AI chat app built in React Native with OpenAI's Responses API streamed over native WebSockets, a Liquid Glass composer, smooth native animations, and Pinecone-backed RAG.
Dave Mkpa-Eke
Rewriting Rive React Native with Nitro Modules: up to 94× Faster Multi-View Loads
Up to 94× faster multi-view load times, 4.7× lower memory, and 3.2× faster property writes: we rebuilt the Rive React Native SDK on Nitro Modules - not just for speed, but to express a natural API for Rive's object model. That architecture is what drives the gains.
Miklós Fazekas
Chasing a Phantom Jump: How We Made Pingo's Animations Smooth on Low-End Android
A deep dive into Skia, Reanimated and Hermes performance on budget Android: why a spring whose math is perfectly monotonic can still look like it jumps, and how the way Skia composites a canvas on Android turned out to be the single biggest cost.
Vishesh Raheja
Building a Video Call App with Filters
Real-time camera filters for React Native video calls (background blur, virtual backgrounds, Center Stage, and live drawing), built by driving the camera with VisionCamera and injecting custom frames straight into WebRTC.
Ritesh Shukla
Four Years of React Native Quick Crypto: From Wallets to Node Parity
How a JSI-based hash-and-HMAC library written for the 2022 Web3 wave grew into a full Node crypto implementation on mobile, with WebCrypto, post-quantum signatures, six phases of security audit, and weekly download counts five times what they were a year ago.
Brad Anderson
Part 2: Making JSI Faster with more Efficient Data Structures
How data shape, API design, and string building impact JSI performance — with real benchmarks and up to 30x speedups.
Alex Shumihin
Part 1: How to Make Pure JSI Code Faster in React Native
A deep dive into JSI performance: HostFunction vs HostObject, NativeState, stack allocation, and reducing JS ↔ C++ crossings, with benchmarks showing where the real gains come from.
Alex Shumihin
QR and Barcode Scanning in React Native with VisionCamera V5
A complete, production-ready guide to scanning QR codes and barcodes in React Native using VisionCamera V5 - the new MLKit-based Code Scanner, the native Object Output for iOS, and frame processors for full control.
Marc Rousavy
