Senior Software Engineer, Backend (Test Enablers)

Senior Software Engineer, Backend (Test Enablers)

Affirm is reinventing credit to make it more honest and friendly. We're looking for a Senior Software Engineer to join our Test Enablers team within Test Platform Engineering (Developer Productivity). You'll design and build platform systems that enable Affirm engineering teams to test with confidence through synthetic identities, test data seeding, mocking, deterministic workflows, and load testing.

About the Role

The Test Enablers team builds and operates platforms that provide synthetic identities, test data seeding, mocking, deterministic testing workflows, and load testing capabilities. Developer Productivity's mission is to dramatically accelerate software development at Affirm while keeping systems reliable for customers. This role is central to scaling validation systems that are fast, trustworthy, automated, and scalable.

You'll design platform capabilities that help engineers validate product changes earlier, run safer load tests, reduce reliance on expensive E2E-only validation, and improve CI signal reliability. You'll also help prepare Affirm's testing infrastructure for AI-assisted development workflows that require deterministic, observable, and actionable validation feedback.

Responsibilities

• 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 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 across engineering teams
• Partner with product engineering and infrastructure teams to improve test signal quality, reduce false failures, and support faster validation loops
• Lead medium-to-large technical projects from problem definition through design, implementation, rollout, and operational ownership
• Improve reliability and operational maturity through dashboards, SLOs, alerts, runbooks, and clear ownership models
• Reduce manual operational load for load testing, including test data creation, environment setup, reporting, and failure diagnosis
• Write high-quality, maintainable code that is easily understood and extended by others
• Contribute to technical specs, RFCs, and architectural decision records

Requirements

• Senior-level backend software engineering experience
• Experience designing and operating scalable systems
• Demonstrated ability to lead medium-to-large technical projects
• Strong foundation in testing infrastructure, validation systems, or developer tooling
• Ability to work effectively with cross-functional teams

Location & Work Arrangement

Remote, Poland