Staff Fullstack Software Engineer (Fintech)

TL;DR

Staff Fullstack Software Engineer (Fintech): Leading technical strategy and architectural decisions for the Acquisition & Onboarding team with an accent on building scalable, performant, and accessible user experiences. Focus on mentoring senior engineers, driving operational excellence, and navigating complex technical challenges across mobile, web, and backend systems.

Location: Must be based in Spain

Salary: €103,000–€139,000 per year

Company

Affirm is a financial technology company reinventing credit by providing flexible, transparent payment solutions without hidden fees.

What you will do

• Define long-term technical strategy and architectural direction for the Acquisition & Onboarding team.
• Collaborate with product, design, and analytics to manage technical sustainability and project trade-offs.
• Act as a force multiplier by setting high standards for code quality, design, and operational processes.
• Ensure system availability through robust monitoring, testing, and on-call rotation participation.
• Mentor senior engineers and foster a culture of technical ownership and continuous improvement.
• Drive the delivery of major features and system components through detailed execution planning.

Requirements

• Must be based in Spain (visa sponsorship available).
• 8+ years of professional software engineering experience.
• Proficiency in backend systems using Python, Kotlin, AWS, MySQL, and Kubernetes.
• Experience developing web applications with declarative UI frameworks like React, React Native, or Vue.
• Proven track record of delivering major features and defining technical execution plans.
• Strong verbal and written communication skills for effective cross-functional collaboration.

Culture & Benefits

• 100% subsidized medical, dental, and vision coverage for employees and dependents.
• Flexible Spending Wallets for technology, food, and lifestyle needs.
• Competitive vacation and holiday schedules.
• Employee Stock Purchase Plan (ESPP) and equity rewards.
• Learning and development programs with parental leave support.