# Margelo Blog

> React Native performance notes, architecture writeups, and field reports from the teams building Margelo products and open-source libraries.

Canonical blog: https://margelo.com/blog
LLM index: https://margelo.com/blog/llms.txt
Last updated: 2026-07-30
The links below are clean Markdown versions of the published articles. Prefer each canonical HTML URL when citing or sharing an article.

## Articles

- [Building a Real-Time Face Recognition App in React Native with VisionCamera](https://margelo.com/blog/on-device-face-recognition-react-native/llms.txt): 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. By Patrick Kabwe, Engineering, published 2026-07-30. [Canonical article](https://margelo.com/blog/on-device-face-recognition-react-native).
- [Building a ChatGPT-Style AI Chat App in React Native with RAG & Streaming](https://margelo.com/blog/building-native-llm-chat-app-with-rag/llms.txt): 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. By Dave Mkpa-Eke, AI, published 2026-07-16. [Canonical article](https://margelo.com/blog/building-native-llm-chat-app-with-rag).
- [Rewriting Rive React Native with Nitro Modules: up to 94× Faster Multi-View Loads](https://margelo.com/blog/rewriting-rive-react-native-with-nitro-modules/llms.txt): 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. By Miklós Fazekas, Engineering, published 2026-07-09. [Canonical article](https://margelo.com/blog/rewriting-rive-react-native-with-nitro-modules).
- [Chasing a Phantom Jump: How We Made Pingo's Animations Smooth on Low-End Android](https://margelo.com/blog/profiling-skia-reanimated-low-end-android/llms.txt): 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. By Vishesh Raheja, Performance, published 2026-06-24. [Canonical article](https://margelo.com/blog/profiling-skia-reanimated-low-end-android).
- [Building a Video Call App with Filters](https://margelo.com/blog/building-videocall-app-with-filters/llms.txt): 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. By Ritesh Shukla, Engineering, published 2026-06-18. [Canonical article](https://margelo.com/blog/building-videocall-app-with-filters).
- [Four Years of React Native Quick Crypto: From Wallets to Node Parity](https://margelo.com/blog/four-years-of-react-native-quick-crypto/llms.txt): 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. By Brad Anderson, Security, published 2026-06-11. [Canonical article](https://margelo.com/blog/four-years-of-react-native-quick-crypto).
- [The Go-To Guide for Understanding Keyboards in React Native (Part 1)](https://margelo.com/blog/deep-dive-in-keyboard-handling/llms.txt): 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. By Kirill Zyusko, UI, published 2026-05-26. [Canonical article](https://margelo.com/blog/deep-dive-in-keyboard-handling).
- [Part 2: Making JSI Faster with more Efficient Data Structures](https://margelo.com/blog/make-jsi-run-faster-2/llms.txt): How data shape, API design, and string building impact JSI performance — with real benchmarks and up to 30x speedups. By Alex Shumihin, Performance, published 2026-04-28. [Canonical article](https://margelo.com/blog/make-jsi-run-faster-2).
- [Part 1: How to Make Pure JSI Code Faster in React Native](https://margelo.com/blog/make-jsi-run-faster/llms.txt): 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. By Alex Shumihin, Performance, published 2026-04-23. [Canonical article](https://margelo.com/blog/make-jsi-run-faster).
- [QR and Barcode Scanning in React Native with VisionCamera V5](https://margelo.com/blog/react-native-qr-barcode-scanner-visioncamera-v5/llms.txt): 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. By Marc Rousavy, Engineering, published 2026-04-22. [Canonical article](https://margelo.com/blog/react-native-qr-barcode-scanner-visioncamera-v5).
- [How Margelo Helped Discord Improve React Native's New Architecture Performance](https://margelo.com/blog/margelo-discord-react-native-performance/llms.txt): A deep dive into Reanimated internals, Fabric's Shadow Tree, and the fix behind Discord's android performance recovery. By Hanno Gödecke, Performance, published 2026-04-21. [Canonical article](https://margelo.com/blog/margelo-discord-react-native-performance).
- [What's New in VisionCamera V5?](https://margelo.com/blog/whats-new-in-visioncamera-v5/llms.txt): 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. By Marc Rousavy, Engineering, published 2026-04-16. [Canonical article](https://margelo.com/blog/whats-new-in-visioncamera-v5).