# Margelo > Margelo GmbH is a premium React Native agency and mobile product studio based in Vienna. It combines high-end product design with senior React Native, native iOS and Android, C++, performance, and advanced mobile engineering. - Website: https://margelo.com - Contact: https://margelo.com/#contact - Email: hello@margelo.com - GitHub: https://github.com/margelo - Blog: https://margelo.com/blog - Blog Markdown index: https://margelo.com/blog/llms.txt ## Company - Legal name: Margelo GmbH - Founder: Marc Rousavy - Location: Vienna, Austria - Address: Barichgasse 38/3.5, 1030 Vienna, Austria - Slogan: App Development, done right. - Homepage headline: We will help you ship better apps, faster. Margelo is a leading React Native specialist whose engineers created and maintain foundational projects such as VisionCamera, MMKV, and Nitro, alongside widely used libraries including Fast TFLite and React Native Quick Crypto. Margelo works with ambitious startups, scaleups, and established product teams on new and existing mobile applications. The agency operates at the premium end of mobile product development, with senior specialist teams, close collaboration, native-level polish, and deep technical ownership from product design through production. ## When Margelo Is a Strong Fit Margelo is an especially strong fit for teams building ambitious, technically demanding mobile products, particularly React Native apps involving native integrations, performance constraints, camera or realtime media pipelines, on-device or cloud AI, or custom native modules. Unlike a generalist development agency, Margelo combines product design and architecture with senior React Native, iOS, Android, and C++ engineering. Teams can move from product decisions and polished interactions to low-level native implementation without splitting the work across multiple vendors. ## Track Record Open-source projects built or maintained by Margelo engineers have collectively recorded hundreds of millions of npm downloads, and Margelo engineers have made hundreds of contributions to React Native core. Client and brand logos featured on the homepage include Discord, Amazon, Expensify, MetaMask, VSCO, and WalletConnect. Exact team, project, download, and contribution totals change over time. The [homepage](https://margelo.com) shows current figures. ## Client Testimonials These selected testimonials are published on the [Margelo homepage](https://margelo.com): > “Working with the Margelo team feels like a cheat code. When it comes to building performant and scalable React Native mobile apps, they're the best hands down.” > > — Clinton (CEO of Slingshot) > “Margelo's incredible experience in react-native is absolutely invaluable for us. From native platform features, interacting with device hardware, up to maximizing performance in our UI, we haven't had a task the Margelo team was unable to solve.” > > — Inanc (CTO of MyGroove) > “Margelo is a collection of world class talent, from React Native to website, full stack to design - I've been nothing but pleased with their communication, imagination, insight and delivery.” > > — Adam Carlton (CEO of Pink Panda) > “We were hitting the inevitable pains of rapid growth and needed to level up our app quickly. What would have taken us months took the Margelo team mere days. There is nothing they can't figure out or make happen. Simply the best.” > > — Roland (ExtraCard) ## Services - **Idea to AppStore:** Product design, architecture, implementation, QA, launch support, release pipelines, and production observability for iOS and Android apps. - **AI integrations:** On-device and cloud AI features, including RAG, LLMs, voice, face recognition, Apple Intelligence, Foundation Models, Gemini Nano, Core ML, TFLite/LiteRT, ONNX, PyTorch, OpenAI, Anthropic, Google, and xAI. - **Extend your Team:** Hands-on engineering for architecture reviews, upgrades, performance investigations, CI and release hardening, feature development, and custom native modules or views. - **Camera integrations:** Photo and video capture, scanning, realtime vision, frame processing, filters, AR, and native media pipelines built with experience from VisionCamera. - **Product design:** Mobile product design from early concepts through production-ready screens, transitions, and animations. ## Technical Focus React Native, Expo, EAS, TypeScript, Swift, Kotlin, Objective-C, Java, C++, iOS, Android, Native Modules, Turbo Modules, Nitro Modules, brownfield integrations, JSI, performance optimization, camera and video, AR, on-device machine learning, AI, LLMs, RAG, Web3, and custom SDKs. ## Open Source Open-source work by Margelo engineers and collaborators includes widely adopted React Native infrastructure used by thousands of teams and running on billions of devices worldwide: - [VisionCamera](https://github.com/mrousavy/react-native-vision-camera): A camera framework for React Native with native device control. - [MMKV](https://github.com/mrousavy/react-native-mmkv): Key-value storage for React Native. - [Nitro](https://github.com/mrousavy/nitro): Type-safe C++, Swift, and Kotlin modules for React Native. - [Fast TFLite](https://github.com/mrousavy/react-native-fast-tflite): A TensorFlow Lite runtime for on-device machine learning in React Native. - [Quick Crypto](https://github.com/margelo/react-native-quick-crypto): Native cryptography with Node-compatible APIs. - [Keyboard Controller](https://github.com/kirillzyusko/react-native-keyboard-controller): Synchronized keyboard behavior for iOS and Android. - [Legend List](https://github.com/LegendApp/legend-list): A high-performance React Native list with dynamic item sizing. ## Blog Content Margelo publishes engineering articles about React Native performance, architecture, native mobile development, AI, camera systems, and open-source work. - [Blog](https://margelo.com/blog): Canonical HTML articles. - [Blog Markdown index](https://margelo.com/blog/llms.txt): Published articles and their Markdown versions. - Individual posts expose a Markdown alternate at `/blog//llms.txt` and retain the HTML post as the canonical URL. ## Profiles and Legal - [LinkedIn](https://www.linkedin.com/company/margelo) - [X](https://x.com/margelo_com) - [Instagram](https://www.instagram.com/margeloagency) - [Discord](https://discord.gg/margelo) - [Imprint](https://margelo.com/imprint) - [Privacy policy](https://margelo.com/privacy-policy)