Senior Full-Stack Engineer

About the client:

Our client is building the future of money: a fully global, non-custodial app that works like a bank account inside your phone, with no bank in the middle. Users stay in control of their money and can spend and move it instantly and for free across borders—without ever touching the complexity of crypto or self-custody, which the platform removes entirely. It is crypto-heavy at its core but feels completely familiar to a mainstream consumer. Today, the platform serves thousands of customers across 130+ countries, with a current growth focus on young adults in the US.

The company recently closed a $5M seed round (unannounced) from leading US and European investors, providing years of runway. It is a small, highly technical team—currently three full-time engineers—that ships fast and cares deeply about product experience and polish.

Founders:

• CEO: Previously co-founded Aragon, building core early-Ethereum infrastructure that holds $30B+ in value.
• Co-Founder: Formerly the youngest executive at Allfunds, a European bank with $1.5T in assets under management

About the Role

The second of two equal-priority founding-level hires. A senior, generalist full-stack engineer who owns features end-to-end across Tuyo's stack - backend (Node/TypeScript), app, and integrations - rather than being tied to one layer. Same shared-ownership model, same bar on quality and speed. This funnel captures strong generalist engineers; it overlaps heavily with the React Native role.

Key Responsibilities:

• Own and ship features end-to-end across the stack, from backend and APIs to the app layer.
• Write clean, reliable TypeScript that scales with the product and team.
• Work directly with founders, product, and design; move fast from concept to production.
• Make pragmatic architecture decisions and help set engineering standards and tooling.
• Contribute to product quality and polish across all touchpoints.
• Debug and reason through complex product and technical problems end-to-end.

Requirements

• 5+ years of professional software engineering experience shipping production software.

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• Strong full-stack ability - comfortable across backend and frontend; fast to learn new tech.
• Deep proficiency in JavaScript/TypeScript (Node.js on the backend).

Bonus Skills

• React / React Native.
• EVM / Solidity or other crypto experience (a plus, not required).
• Infrastructure: AWS, Kubernetes, Terraform.
• Consumer product / fintech experience.
• Early-stage startup experience; helped define engineering culture or standards.

Logistics

Location:

Madrid or Miami. In-office every day, with ~25% of days at the employee's discretion to work elsewhere. Candidates unwilling to relocate to Madrid or Miami won't be considered

Compensation:

Miami up to $250K base; Madrid ~$100K-$150K USD. Equity ~0.3%-0.6% at this stage. 

Benefits/Other

Significant equity ownership; large individual AI-tooling budget; relocation expected for non-local candidates.

Interview Process:

1. First interview - either with CEO or an initial technical interview with the Head of Engineering.
2. Call with the founders.
3. Half-day to full-day on-site with the team before an offer.