Full-stack Engineer - Payments (Spain)

Join Crossmint as a Full-stack Engineer in Spain to build payment infrastructure for stablecoin and wallet platforms, with a salary of $150k-$200k.

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.

Trusted by more than 40,000 clients including global leaders such as MoneyGram, WireX, Toku, and more, Crossmint provides embedded smart wallets, on/offramps, cross-chain stablecoin orchestration, tokenization, and other blockchain primitives through simple, developer-friendly APIs that integrate in minutes and scale to millions of users.

## What you'll do

• •Design and build payment infrastructure: processor integrations, transaction pipelines, settlement and reconciliation workflows, and the APIs clients depend on.
• •Own critical financial flows end to end, including failure modes, retry logic, state management, and edge cases that matter in production.
• •Work across the stack: backend-heavy, but you will contribute to APIs, dashboards, and the interfaces clients use to interact with payment systems.
• •Ensure data integrity across providers and chains: balances, transaction states, and audit trails that stay consistent even when third-party systems don't.
• •Contribute to architecture decisions: write design docs, review peers' proposals, and help the team make good long-term calls.
• •Participate in on-call rotations (paid, once or twice per quarter) and own incidents on the systems you build.
• •Help onboard and mentor newer engineers as the team grows.

## Conditions

• •Extensive access to leading AI tools and subscriptions, with AI actively encouraged and integrated into daily workflows.
• •Stock options program.
• •Two performance reviews annually.
• •Unlimited Paid Time Off.
• •Parental Leave program.
• •Company laptop + Annual home office and productivity stipend.
• •Daily stipend for in-office meals and/or commuting to the office.
• •Three company-paid off-sites each year.
• •Health + Dental insurance fully covered by Crossmint.
• •Flexible retribution with tax benefits through Cobee.

• •4+ years building and maintaining production backend systems, ideally involving financial data, payments, or transaction-critical infrastructure.
• •Strong proficiency in TypeScript or JavaScript (our primary stack), or another typed modern language with willingness to move quickly.
• •Solid understanding of distributed systems fundamentals: idempotency, consistency guarantees, failure handling, async workflows.
• •Fluent in English, written and spoken.
• •Hands-on integration experience with Stripe, Adyen, or similar payment processors.
• •Exposure to stablecoin infrastructure, crypto payments, wallets, or cross-chain systems.
• •Experience operating financial systems in regulated environments.