Senior Software Engineer, Backend (Test Enablers) at Affirm

✨ The Stack take on this Affirm job

• 🏢 Affirm has 38 jobs here, 25 with visa sponsorship see all
• 🛂 Visa: Highly Qualified Professional permit. Education: Higher education degree guide
• 💡 No salary shown. Ask Affirm if it is above the minimum.

Updated 2026-11-05, from our data and official sources.

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About the role

Responsibilities:
- Design, build, and operate scalable platforms for synthetic identities, test data seeding, mocking, deterministic workflows, and load testing.
- Shift testing strategy from E2E-heavy validation to a mix of component, integration, contract, performance, and targeted E2E tests.
- Make production-like load testing safer and repeatable with automation, environment orchestration, and repeatable data setup.
- Improve observability and reliability: implement dashboards, SLOs, alerts, runbooks, and clear ownership for test infrastructure.
- Lead medium-to-large technical projects from problem definition through rollout and operational ownership; review designs and mentor engineers.

Requirements:
- 5+ years of software engineering experience with strong backend skills in Python, Kotlin, or Java.
- Proven experience building distributed systems, developer tooling, or platform infrastructure for testing and CI/CD.
- Strong knowledge of test automation, load testing, observability, and failure diagnosis practices.
- Experience writing technical specs (RFCs, ADRs) and driving cross-team alignment.
- Excellent communication and mentorship skills; comfortable working with product teams to improve test signal quality.

Responsibilities

Design and maintain scalable platforms for synthetic identities, test data seeding, and load testing to accelerate software development. Lead technical projects to evolve the testing strategy from E2E-heavy validation toward a more scalable, deterministic model.

Requirements

Requires 5+ years of software engineering experience with strong backend skills in Python, Kotlin, or Java. Must have experience building distributed systems or developer tools and the ability to drive ambiguous technical projects to completion.

Key skills

• Python — in 1200 other listings on The Stack
• Kotlin — in 251 other listings on The Stack
• Java — in 360 other listings on The Stack
• Distributed Systems — in 342 other listings on The Stack
• Platform Infrastructure — not in any other listing on The Stack
• System Design — in 199 other listings on The Stack
• Test Automation — in 87 other listings on The Stack
• CI/CD — in 630 other listings on The Stack
• Load Testing
• Observability
• Backend Engineering
• API Mocking
• Contract Testing
• Integration Testing
• Technical Specification Writing
• Mentoring

On The Stack (as of 2026-11-05)

• Affirm has 37 other listings on The Stack, 24 of them marked as offering visa sponsorship.
• 76 visa-sponsored jobs in Spain on The Stack, posted in the last 60 days.
• 195 visa-sponsored software engineer jobs in Europe on The Stack, posted in the last 60 days.

Frequently asked questions about Affirm

Is this Senior Software Engineer, Backend (Test Enablers) role still open?

It was posted on 2026-07-01. Listings more than 30 days old may no longer be active, so check Affirm's site before applying.

Does Affirm offer visa sponsorship?

This listing is marked as offering visa sponsorship. Eligibility rules are set by the employer, so check the details on Affirm's site.

Where is this role located?

The listing gives the location as Spain. It is marked on-site.

What skills does this role ask for?

The listing names: Python, Kotlin, Java, Distributed Systems, Platform Infrastructure, System Design, Test Automation, CI/CD, Load Testing, Observability, Backend Engineering, API Mocking, Contract Testing, Integration Testing, Technical Specification Writing, Mentoring.