This talk was presented during the React Native EU 2021 - the largest community conference in the world focused exclusively on React Native. Abstract: Mobile apps could be vulnerables. There is a lot of tools for penetration testing, disassembling and software forensics, and if we don't protect our apps, the source code, our secrets, or even users data, could be in danger. In this talk, we gonna see some tools and technics to understand how to prevent the app from being hacked, and what things you should consider about store/handle user data. Hi ! I'm Mateo Silguero, a mobile developer based on Argentina. I'm 25 years old, and a huge fan of React Native and web technologies. Lately im focusing on mobile security. I work at ank (https://www.ank.app/) a fintech startup from my country. Twitter: https://twitter.com/mateosilguero1 Github: https://github.com/mateosilguero Additional Links: slides: https://drive.google.com/file/d/18_69vtdHZJzUWlh6n_TOOOL_Pk4dQdaJ/view?usp=sharing demo code: https://github.com/mateosilguero/rn-eu-2021