Senior Software Engineer, Backend (Partner Merchant Interface)

Affirm; Seattle (WA); Remote; USD 195,000 - 255,000; Full time

Benefits offered by this job

100% employer health coverage

Monthly tech stipends

Generous holiday schedule

Employee stock purchase plan

Job summary

Affirm is a remote-first company making pay-over-time simple and transparent. The Partner Merchant Interfaces - Integration team builds APIs for Partners and Merchants and powers top partners like Amazon and Stripe.

You will design and ship backend services at scale using Python or Kotlin, with AWS, MySQL and Kubernetes, delivering well-tested, extensible code and owning your growth within a global engineering team.

Qualifications

• Experience designing, developing and launching backend systems at scale.
• Proficient in Python or Kotlin and modern backend tools.
• Able to own components and review code with stakeholders.

Responsibilities

• Develop and maintain APIs used by Partners and Merchants.
• Collaborate with teams to ensure reliable, scalable services.
• Balance speed and quality while protecting systems from downtime.

Skills

Backend design

Python/Kotlin

Distributed systems

Code reviews

Ownership & growth

Education

Bachelor's degree or equivalent

Tools

AWS

MySQL

Kubernetes

Job description

At Affim, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most.

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

Remote-first with flexibility built in

Affirm is proud to be a remote-first company. Most roles can be done from almost anywhere within the country of employment. Some positions may occasionally require in-person work at an affirm office, and a few are office-based due to the nature of the work. All new hires will be invited to attend an in-person onboarding experience.

Benefits Designed For You

• Health coverage at no cost: We cover 100% of premiums for employees and their dependents.
• Spending stipends: Monthly stipends support your tech setup, and the ability to choose health and wellness options that are right for you.
• Time off to recharge: Flexible time off and generous holiday calendars help you rest when you need to.
• Own a piece of what you build: Our employee stock purchase plan (ESPP) lets you buy affirm stock at a discount.

We’re committed to providing an inclusive interview process, including accommodations for candidates with disabilities. If you need support, we’re happy to help.

For positions based in San Francisco or Los Angeles: affirm considers qualified applicants with arrest and conviction records, as required by law.