Senior Backend Software Engineer – Partner Merchant Interface

About the role

Affirm is looking for a Senior Backend Software Engineer to join the Partner Merchant Interfaces – Integration team. You will help design, build, and maintain the APIs that enable partners and merchants, including top platforms such as Amazon and Stripe, to integrate with Affirm’s payment solutions.

Key responsibilities

• Develop and evolve high‑performance, scalable backend services used by external partners.
• Collaborate closely with product, design, and other engineering teams to define requirements and deliver features.
• Balance speed of delivery with system reliability, ensuring minimal downtime.
• Participate in code reviews, debugging, and refactoring of a large, distributed codebase.
• Contribute to team culture through mentorship, knowledge sharing, and community activities.

Required profile

• Professional or internship experience designing, developing, and launching backend systems at scale.
• Strong problem‑solving ability to translate business scenarios into robust, multi‑component solutions.
• Self‑driven growth mindset with a track record of seeking feedback and continuous improvement.
• Excellent verbal and written communication skills for effective collaboration across a global engineering organization.
• Either equivalent practical experience or a Bachelor’s degree in a related field.

Required skills

• Proficiency in Python or Kotlin.
• Experience with AWS services.
• Strong knowledge of MySQL databases.
• Familiarity with Kubernetes for container orchestration.
• Understanding of distributed system fundamentals.

What we offer

• Base salary ranging from $173,000 to $255,000 per year (USD), depending on location and experience.
• Equity rewards and monthly stipends for health, wellness, and technology spending.
• Comprehensive benefits including 100% subsidized medical, dental, and vision coverage for employees and dependents.
• Remote‑first work model with flexibility to work from anywhere in the United States.