Senior Full Stack Mobile Engineer (Web3 & Fintech)

The Mission

Crush Rewards is building the ultimate bridge between traditional consumer behavior and the decentralized future. We’re not just another rewards app; we’re a contribution network where everyday actions—like scanning a receipt and linking credit card spending—are transformed into on-chain value.

We are looking for a Full Stack Mobile Engineer who thrives at the intersection of high-performance mobile interfaces, robust backend architecture, and the Solana blockchain. You will own features end-to-end: from crafting a "buttery-smooth" UI to architecting the backend pipelines that verify financial data and trigger token emissions.

What You’ll Do

• Architect the Frontend: Lead the development of our React Native (Expo) app, ensuring high-performance execution of complex features like real-time token charts and deep-linked wallet interactions.
• Build Robust Backend Pipelines: Own the Node.js/Express API that powers our ecosystem. You'll manage critical backend logic including receipt OCR verification, transactional syncs with credit cards, product rewards calculations, and user progression systems (streaks, levels, milestones).
• Execute Web3 Strategy: Implement and scale our Solana integration. You will manage custodial wallet flows with Crossmint, execute on-chain token swaps via Jupiter, and handle complex staking/unstaking logic.
• Own the Data Lifecycle: Manage a scalable PostgreSQL architecture, ensuring real-time data consistency across user profiles, streaks, and transaction histories.
• Iterate with Quality: Advocate for best practices in TypeScript, automated testing, and CI/CD (EAS/GitHub Actions) to ensure we ship high-quality code to the App Store and Play Store multiple times a week.
• Drive Growth through Data: Use PostHog analytics and OneSignal engagement tools to understand user behavior and build the features that keep our users "Crushing" their goals.

What You’ll Need

• The TypeScript Professional: You have 4+ years of experience in professional software engineering, with a mastery of TypeScript across the entire stack.
• Mobile Expertise: Deep experience with React Native (Expo). You understand the mobile lifecycle, performance optimization, and how to build responsive UIs using modern toolkits.
• Backend Proficiency: Strong experience with Node.js and PostgreSQL. You know how to design clean APIs and manage complex relational data at scale.
• Web3 Literacy: You are comfortable with the Solana ecosystem (web3.js, SPL tokens). You understand how to interact with smart contracts and manage the security implications of blockchain transactions.
• Fintech Experience: Practical experience integrating third-party financial APIs and handling sensitive user data with a "security-first" mindset.
• Product Intuition: You care about the "Why" behind a feature. You can translate a Figma design into a functional reality while suggesting improvements to the user flow. Bonus points if you can create clean UI components without Figma.

Our Tech Stack

• Mobile: React Native, Expo, TypeScript.
• Backend: Node.js, Express, PostgreSQL, Edge Functions.
• Blockchain: Solana (Web3.js), SPL Tokens, Crossmint, Jupiter SDK.

Bonus Points

• You’ve built or contributed to a Solana Anchor program (Rust) and/or typescript SDKs.
• Experience with AI/LLM pipelines for data extraction or personalized user experiences.
• Background in a high-growth startup where you wore multiple hats and "owned" the outcome.
• A passion for the "Rewards" space and an understanding of gamification mechanics (streaks, levels, milestones).

Why Join Us?

At Crush Rewards, we're a small, focused team where every member has significant impact and ownership. You won't just be a "cog in the machine"—you will be the architect of a platform that redefines how millions of people interact with their money and the blockchain. We value clean code, fast iteration, and a relentless focus on the user experience.

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