Senior Software Engineer (React Native)
Onhires
Location: Madrid, Spain (Slightly Preferred) or Miami, FL - 100% In-Person (Daily in-office, ~25% flexible remote days).
Company Size: Early stage (3 full-time engineers).
Mission: Global, non-custodial web3 banking app with a flawless mainstream UX.
About Tuyo
We are building a global, non-custodial app that works like a bank account inside your phone, removing all the complexity of crypto for the end user.
The Traction: $5M Seed round from top US/EU investors. Operating in 130+ countries with a viral Visa debit card product.
The Founders: Jorge Izquierdo (co-founder of Aragon, built core Ethereum infrastructure holding $30B+) and Alejandro Perezpayá (ex-Allfunds, $1.5T AUM bank).
The Role
As one of our first founding-level engineering hires, you will own major parts of Tuyo’s React Native app end-to-end. We run a shared-ownership model across the whole stack-mobile is your entry point, not a boundary. We deeply care about product feel, animations, and delighting users.
Key Responsibilities:
Own features end-to-end: from UI and state management to API integration, testing, and App Store releases.
Write clean, reliable TypeScript/JavaScript that scales.
Work directly with founders and designers; move fast from concept to production without waiting for perfect specs.
Debug tricky performance issues across iOS, Android, and backend layers.
Help set early engineering culture, architecture standards, and tooling.
Requirements
5+ years of professional software engineering experience.
Strong track record of shipping and optimizing production apps in React Native.
Deep proficiency in TypeScript / JavaScript.
Founder Mindset: High agency, extreme ownership, low ego. You care about product taste and user experience.
In-Person: Based in (or willing to relocate to) Madrid or Miami.
Nice-to-Haves:
Experience with Expo, native modules, and mobile CI/CD.
Backend / Full-stack experience (Node.js, APIs).
Crypto/EVM familiarity (a plus, but genuine interest is enough).
Heavy use of AI tooling to multiply your engineering output.
What We Offer
High-tier base salary + meaningful founding-level equity (0.3%-0.6%).
Large individual AI-tooling budget.
Relocation support for non-local candidates.