Senior Software Engineer, Backend (Test Enablers)

TL;DR

Senior Software Engineer, Backend (Test Enablers) (Developer Productivity): Building and operating platforms for synthetic identities, test data seeding, and load testing with an accent on system reliability and scalability. Focus on reducing reliance on E2E validation and preparing infrastructure for AI-assisted development workflows.

Location: Must be based in Spain (Visa sponsorship available)

Salary: €86,000 - €122,000 per year

Company

Affirm is a fintech company reinventing credit to make it more honest and friendly through transparent buy now, pay later solutions.

What you will do

• Design and maintain scalable systems for synthetic identities, mocking, and load testing.
• Evolve the testing strategy from E2E-heavy validation toward component, integration, and contract testing.
• Build platform capabilities to make production-like load testing safer, more repeatable, and easier to operate.
• Partner with product and infrastructure teams to improve test signal quality and reduce false failures.
• Lead medium-to-large technical projects from ambiguous definition through implementation and operational ownership.
• Mentor engineers and contribute to technical specs, RFCs, and ADRs to raise engineering standards.

Requirements

• 5+ years of software engineering experience.
• Strong backend expertise in Python, Kotlin, Java, or similar languages.
• Experience designing and operating distributed systems, platform infrastructure, or internal developer tools.
• Strong fundamentals in system design, debugging, reliability, and production operations.
• Ability to independently drive ambiguous technical work to completion.
• Must be based in Spain.

Culture & Benefits

• Remote-first environment with flexibility within the country of employment.
• 100% subsidized medical, dental, and vision coverage for employees and dependents.
• Flexible Spending Wallets for technology, food, and lifestyle needs.
• Wellness "Away Days" and comprehensive Learning & Development programs.
• Equity rewards and an Employee Stock Purchase Plan (ESPP).