Senior Software Engineer, Backend (Test Enablers)

Affirm is reinventing credit to make it more honest and friendly, giving consumers the flexibility to buy now and pay later without any hidden fees or compounding interest.

The Test Enablers team within Test Platform Engineering (Developer Productivity) builds and operates platforms for synthetic identities, test data seeding, mocking, deterministic testing workflows, and load testing. The role is central to scaling to 1,000 PRs per day by December 2027.

• Design, build, and maintain scalable systems for synthetic identities, test data seeding, mocking, load testing, and deterministic validation workflows.
• Evolve Affirm's testing strategy from broad E2E-heavy validation toward a more scalable model with stronger component, integration, contract, performance, and targeted E2E testing.
• Build platform capabilities that make production-like load testing safer, more repeatable, and easier to operate.
• Improve test platform reliability, observability, and adoption.
• Lead medium-to-large technical projects from ambiguous problem definition through design, implementation, rollout, and operational ownership.
• Mentor engineers and help build a culture of practical testing excellence.

• 5+ years of software engineering experience.
• Strong backend engineering experience with Python, Kotlin, Java, or similar languages.
• Experience designing, building, and operating distributed systems, platform infrastructure, internal developer tools, or testing infrastructure.
• Strong ownership and ability to independently drive ambiguous technical work to completion.
• Experience improving system reliability, observability, operational maturity, and maintainability.
• Excellent written and verbal communication skills, including async artifacts such as technical specs, RFCs, ADRs, and project plans.
• Experience with test automation frameworks, test data systems, mocks, contract testing, integration testing, load testing and CI/CD platforms.

Base pay range: €86,000 - €122,000 per year. Additional benefits include equity rewards, monthly stipends for health, wellness and tech spending, 100% subsidized medical coverage, dental and vision for you and your dependents, Flexible Spending Wallets, Away Days, Learning & Development programs, Parental benefits, Employee Resource & Community Groups, and ESPP.

Remote Spain. Visa sponsorship is available, but the role requires being based in Spain.

Apply via the provided link.