Mobile Engineer

Mobile Engineer

Fin is a next-generation payments platform built for high-value, global, and instant transactions. We are a Series A-stage company backed by Sequoia, Circle, and other notable investors. Powered by stablecoins, Fin enables users and businesses to move millions of dollars in seconds - whether to other Fin users, directly into bank accounts, or across crypto rails. By combining the speed of crypto with the reliability and trust of traditional finance, Fin reimagines how money moves worldwide. If banks and payment products were reinvented today, they would look like Fin.

We are looking for a Mobile Engineer to own our mobile experience across iOS and Android using React Native. This will be the first time many users interact with Fin, so your work will define how our product feels in the real world. You will turn messy real world payment flows into simple, intuitive interfaces, and help hide the complexity of crypto, wallets, and cross border settlement behind a smooth mobile experience.

You will work closely with the founders and the rest of the engineering team, make foundational decisions about architecture and design, and ship features from idea to production. If you care about building delightful consumer products on top of serious infrastructure, this is for you.

We value your time: our process focuses on practical system design and architectural discussions, not LeetCode grinding or unpaid take-home assignments.

Responsibilities

• Own the Fin mobile app across iOS and Android using React Native, from architecture to implementation and polish.
• Design and implement flows that make sending, receiving, and managing money feel simple and trustworthy for everyday users.
• Help design secure account and custody patterns that can scale to handle meaningful balances and real world usage.
• Collaborate with design and product to prototype, refine, and ship new features quickly.
• Maintain a high bar for code quality through thoughtful architecture, code review, and testing.
• Work with backend and infra engineers to integrate APIs, payments, and identity or security features into the mobile app.

Qualifications

• 3+ years of experience building and shipping mobile apps in React Native. Deep familiarity with the Expo ecosystem and modern mobile build pipelines (EAS) is required.
• Strong product sense and attention to detail in UI and UX, especially for consumer facing apps.
• Solid understanding of mobile app architecture, performance, and offline or edge cases.
• Ability to work independently, set priorities, and drive projects from idea to shipped.
• Strong communication skills and comfort collaborating with design, product, and backend teams.
• Interest in payments, fintech, or crypto. You do not need to be a chain maximalist, but curiosity about the space helps.

Bonus Points

• You have shipped an app from concept to production in a small team or as the primary developer.
• Experience in traditional consumer fintech apps (neobanks, peer-to-peer payments) OR mobile crypto wallets (Solana, non-custodial, etc).
• Experience with cloud platforms such as GCP or AWS.
• Experience deploying smart contracts on Solana or integrating with blockchain based systems.
• Background in security, threat modeling, or penetration testing, especially for consumer finance products.