Fullstack Engineer

Full-stack Engineer (Spain)

Engineering Madrid Hybrid

Crossmint is the leading enterprise‑grade, all‑in‑one stablecoin and wallet infrastructure platform enabling fintechs and enterprises to integrate stablecoin rails and smart wallets with speed, compliance, and scale.

Backed by Ribbit Capital, Franklin Templeton, NYCA, First Round, and Lightspeed Faction, with $23.6M raised in 2025. Trusted by more than 40,000 clients including global leaders such as Money Gram, WireX, Toku, and more, Crossmint provides embedded smart wallets, on/off‑ramps, cross‑chain stablecoin orchestration, tokenization, and other blockchain primitives through simple, developer‑friendly APIs that integrate in minutes and scale to millions of users.

In January 2026, Crossmint secured MiCA authorization from Spain's CNMV, becoming one of a select few stablecoin infrastructure providers fully licensed to operate across all 27 EU member states and held to the same regulatory standards as traditional financial institutions. Crossmint also powers the Republic of the Marshall Islands' first digital UBI program, backs Money Gram's new stablecoin cross‑border experience launching in LATAM, and recently partnered with WireX to expand multichain stablecoin payment infrastructure to non‑EVM networks like Stellar.

The future of finance is stablecoin‑native. Crossmint makes it easy to get there.

We have offices in Madrid, and we are also open to a full remote setting from Spain.

Full‑time, indefinite contract.

4‑7 years of experience. We are also open to considering candidates with more than 7 years of experience.

As a Full‑stack Engineer at Crossmint, you will help build and maintain core systems that power our products and customer experiences. You will work across the stack to deliver reliable, scalable, and secure solutions that support critical business and financial workflows.

• Write high‑quality code: correct, secure, performant, and maintainable.
• Design and build backend and frontend systems: contribute to APIs, services, and user‑facing applications.
• Develop and maintain financial and transactional workflows: including subscriptions, payments, and usage‑based systems.
• Ensure data integrity and reliability: design and maintain systems that accurately track transactions, balances, and usage.
• Collaborate on system architecture: write and review architectural and design documentation with the team.
• Own projects end to end: from initial design to production deployment and iteration.
• Participate in on‑call rotations: take part in paid on‑call shifts once or twice per quarter.
• Mentor and support teammates: help onboard and guide new engineers.

• Excellent communication skills: strong written and spoken English.
• Educational background:
  Bachelor's degree in Computer Science or a related field, or equivalent professional experience.
• Professional experience: 4+ years building and maintaining production systems, ideally involving financial data, billing, or payments.
• Programming expertise: strong proficiency in at least one modern language such as Typescript, Java script, Java, Python, Scala, Ruby, or similar.
• Experience with payment systems: familiarity with Stripe or similar payment processors is a strong plus.
• Crypto and web3 experience: prior exposure to blockchain, crypto payments, wallets, smart contracts, or web3 infrastructure is a strong plus, though not a must‑have.
• A product‑oriented mindset: ability to balance technical quality with business impact.
• Diverse applicants are strongly encouraged to apply.

You will own critical systems at the heart of our financial infrastructure, powering subscriptions, payments, and usage for apps used by millions. As a Full‑stack Engineer, you’ll ship end‑to‑end, shape architecture, and solve meaningful challenges alongside a sharp, mission‑driven team. If you want autonomy, impact, and to build the future of onchain development, this is your place!

• Extensive access to leading AI tools and subscriptions, with AI actively encouraged and integrated into daily workflows.
• Stock options program.
• We conduct two performance…