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Senior Software Engineer, Backend (Partner Merchant Interface)

Affirm
Boston, MA Volunteer
POSTED ON 9/10/2026
AVAILABLE BEFORE 10/9/2026
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 Partner Merchant Interfaces - Integration team within Decisions Foundations is growing and we are looking for a Software Engineer. You will be part of a fast paced team which is responsible for the APIs that Partners and Merchants use to integrate with Affirm, and also power some of our top partners like Amazon and Stripe.

What You'll Do

  • With the support of your team, you will work on tasks that contribute to the team's projects and goals.
  • You will work collaboratively and proactively with your team and stakeholders, bringing them along for your work and helping to create visibility and dialog regarding the risks and trade-offs related to your work.
  • You will strike the right balance of speed and quality in your work, ensuring that we hit our business goals while protecting our systems from downtime.
  • You will contribute to a sense of community on your team by engaging in growth and development activities.

What We Look For

  • You have previous work or internship experience designing, developing and launching backend systems at scale and are experienced using one of Python or Kotlin.
  • You are familiar with the building blocks of distributed systems, and the technologies like AWS, MySQL and Kubernetes.
  • You have mastered taking a simple problem or business scenario into a solution that interacts with multiple software components, and executing on it by writing clear, easily understood, well tested and extensible code.
  • You are comfortable navigating a large code base, debugging others' code, and providing feedback to other engineers through code reviews.
  • Your experience demonstrates that you take ownership of your growth, proactively seeking feedback from your team, your manager, and your stakeholders.
  • You have strong verbal and written communication skills that support effective collaboration with our global engineering team.
  • This position requires either equivalent practical experience or a Bachelor’s degree in a related field.

Base Pay Grade - N

Equity Grade - 9

Employees new to Affirm typically come in at the start of the pay range. Affirm focuses on providing a simple and transparent pay structure which is based on a variety of factors, including location, experience and job-related skills.Base pay is part of a total compensation package that may include equity rewards, monthly stipends for health, wellness and tech spending, and benefits (including 100% subsidized medical coverage, dental and vision for you and your dependents.)

USA base pay range (CA, WA, NY, NJ, CT) per year: $195,000 - $255,000

USA base pay range (all other U.S. states) per year: $173,000 - $233,000

LI-Remote

Affirm is proud to be a remote-first company! The majority of our roles are remote and you can work almost anywhere within the country of employment. Affirmers in proximal roles have the flexibility to work remotely, but will occasionally be required to work out of their assigned Affirm office. A limited number of roles remain office-based due to the nature of their job responsibilities.

Benefits

We’re extremely proud to offer competitive benefits that are anchored to our core value of people come first. Some key highlights of our benefits package include:

  • Health care coverage - Affirm covers all premiums for all levels of coverage for you and your dependents
  • Flexible Spending Wallets - generous stipends for spending on Technology, Food, various Lifestyle needs, and family forming expenses
  • Time off - competitive vacation and holiday schedules allowing you to take time off to rest and recharge
  • ESPP - An employee stock purchase plan enabling you to buy shares of Affirm at a discount

We believe It’s On Us to provide an inclusive interview experience for all, including people with disabilities. We are happy to provide reasonable accommodations to candidates in need of individualized support during the hiring process.

[For U.S. positions that could be performed in Los Angeles or San Francisco] Pursuant to the San Francisco Fair Chance Ordinance and Los Angeles Fair Chance Initiative for Hiring Ordinance, Affirm will consider for employment qualified applicants with arrest and conviction records.

By clicking "Submit Application," you acknowledge that you have read Affirm's Global Candidate Privacy Notice and hereby freely and unambiguously give informed consent to the collection, processing, use, and storage of your personal information as described therein.

Salary : $173,000 - $233,000

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