Senior Software Engineer, Backend (Test Enablers)

Overview

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.

Job Description

We are looking for a highly motivated Senior Software Engineer to join our Test Enablers team within Test Platform Engineering (Developer Productivity). The Test Enablers team builds and operates the platforms that allow Affirm engineering teams to test with confidence.

Responsibilities

• - Design, build, and maintain scalable systems for synthetic identities, test data seeding, mocking, load testing, and deterministic validation workflows.
• - Help 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 our test platform so it is reliable, observable, and easier for other teams to adopt.
• - 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 ambiguous 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 can be easily understood and extended by others.
• - Contribute to technical specs, RFCs, ADRs, project plans, and other async artifacts that align teams around technical decisions.
• - Review code and technical designs, provide constructive feedback, and help raise engineering standards.
• - Mentor engineers and help build a culture of practical testing excellence.

Required Skills

• - 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.
• - Ability to collaborate across engineering teams and influence technical direction through clear communication.
• - Excellent written and verbal communication skills, including async artifacts such as technical specs, RFCs, ADRs, and project plans.
• - Strong engineering fundamentals across system design, testing, debugging, reliability, and production operations.
• - Operational ownership of critical internal testing platforms, including reliability, observability, alerting, runbooks, and incident readiness.
• - Experience with test automation frameworks, test data systems, mocks, contract testing, integration testing, load testing and CI/CD platforms.
• - Ability to balance pragmatic delivery with long-term technical quality.
• - Passion for improving developer productivity and product quality through scalable, automated, reliable systems.

Benefits

• - Base pay range per year: €86,000 - €122,000
• - Flexible Spending Wallets for tech, food and lifestyle
• - Away Days - wellness days to take off work and recharge
• - Learning & Development programs
• - Parental benefits
• - Employee Resource & Community Groups
• - 100% subsidized medical coverage, dental and vision for you and your dependents
• - Equity rewards offered by Affirm Holdings, Inc.