Software Engineer, React Native en Madrid, España

Our client is an early-stage financial technology company building a global, non-custodial consumer application that allows users to hold, spend, and transfer money across borders without relying on a traditional bank.

The platform is powered by blockchain technology but is designed to feel familiar and accessible to mainstream users. It removes much of the complexity traditionally associated with cryptocurrency and self-custody while allowing users to remain in control of their funds.

The company serves customers internationally and is currently focused on expanding its presence among younger consumers in the United States.

Backed by leading investors, the business has significant financial runway and operates with a small, highly technical engineering team that values speed, product quality, and ownership.

About the Role

We are looking for a Senior Software Engineer specialising in React Native to join as one of the company’s key early engineering hires.

This role will own major areas of the mobile application from end to end, including user interface development, state management, API integration, testing, deployment, and application releases.

Although the role has a strong mobile focus, engineers work within a shared-ownership model across the entire technology stack. The mobile application is the primary area of responsibility rather than a strict boundary.

The successful candidate will work directly with the founders and take significant ownership over product and technical decisions. Product quality, usability, responsiveness, and attention to detail are central to the role.

Key Responsibilities

Own major areas of the React Native mobile application from initial concept through production release.

Build features across user interface development, state management, API integration, testing, and deployment.

Work directly with founders, product, and design stakeholders.

Move from concept to production without relying on fully defined specifications.

Debug complex issues across iOS, Android, and backend integrations.

Improve application performance, animations, responsiveness, and overall product quality.

Make pragmatic architectural decisions.

Help establish engineering standards, development practices, and tooling.

Contribute across the broader technology stack when required.

Required Experience and Skills

Must Have

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

Strong experience building and releasing production applications using React Native.

Experience owning mobile product features from development through release.

Strong product mindset and attention to user experience.

Ability to work independently within a fast-moving early-stage environment.

Willingness to relocate to and work on-site in Madrid or Miami.

Nice to Have

Experience building consumer-facing mobile products.

Experience with Expo.

Experience developing or integrating native mobile modules.

Familiarity with App Store and Google Play release processes.

Experience with mobile CI/CD pipelines.

Backend or full-stack experience using https://jobeax.com/link/JSd7UYCSg572jJDY and APIs.

Experience with EVM, Solidity, blockchain, or cryptocurrency products.

Early-stage startup experience.

Experience helping establish engineering culture, standards, or tooling.

Ideal Background

The strongest candidates are likely to have founded a company or worked within an early-stage startup where they developed a high-ownership operating mindset.

Experience within cryptocurrency-native products or leading consumer-fintech companies is valuable. However, strong product engineers from smaller or lesser-known companies will also be considered.

The company is particularly interested in senior engineers who care deeply about what users experience rather than focusing only on technical functionality.

Previous cryptocurrency experience is beneficial but not required. Genuine interest in blockchain-based financial products is sufficient.

Core Competencies

Successful candidates will demonstrate:

High agency, extreme ownership, and a founder mindset.

Ability to ship high-quality features quickly and independently.

Strong product judgement and attention to detail.

Ability to own features across the full development lifecycle.

Low ego and strong collaboration skills.

Energy and enthusiasm for the company’s mission.

Comfort working within a small and demanding startup environment.

Willingness to contribute beyond a narrowly defined mobile engineering role.

Effective use of AI development tools to increase engineering output.

Candidate Considerations

Candidates may not be suitable where their experience has been limited primarily to highly structured, large-company environments.

The role is unlikely to suit engineers who:

Prefer a narrowly defined or siloed scope.

Require detailed specifications before beginning work.

Expect a highly structured working environment or traditional nine-to-five schedule.

Are unwilling to relocate to Madrid or Miami.

Are unable to work regularly from the office.

Why Join?

Join as a key early engineering hire with significant technical and product ownership.

Build a global consumer financial product powered by blockchain technology.

Work directly with experienced founders and engineering leadership.

Own major areas of the mobile application from concept through release.

Help establish engineering standards and culture as the team grows.

Receive meaningful equity ownership.

Access a substantial individual budget for AI development tools.

Work within a highly technical, fast-moving, and product-focused team.