Senior Software Engineer, Backend (Merchant & Partner Lifecycle)

Affirm; Sioux Falls (SD); Remote; USD 173,000 - 233,000; Full time

Benefits offered by this job

Health coverage

ESPP

Time off

Flexible spending wallets

Job summary

Affirm is reinventing credit to offer a transparent, flexible buy now, pay later experience. The Merchant & Partner Lifecycle team builds a new lifecycle-orchestrator service, delivering faster availability through architectural simplification and modernization.

You will lead backend design, drive cross-team initiatives, and mentor engineers to grow while shaping the long-term technical vision for the MPL domain.

Qualifications

• 5+ years of backend software engineer experience.
• Strong understanding of Domain-Driven Design and distributed systems.
• Proficiency in data models, API design, state machines, event-driven architectures, and DB design.
• Excellent written and verbal communication, with asynchronous tech specs.

Responsibilities

• Design and expand the backbone of our platform to scale to hundreds of thousands of merchants worldwide.
• Coordinate scope with cross-team projects.
• Mentor engineers to support growth and development.
• Collaborate with Engineering Manager and Team Lead on long-term visions.
• Lead technical strategy for broad or complex requirements beyond the immediate team.
• Leverage tools to automate development processes.
• Improve engineering standards, tooling, and processes across the org.

Skills

Backend engineering

Domain-Driven Design

Distributed systems

API design

Kotlin

Python

Java

Data modeling

Asynchronous communication

Monitoring & alerting

Tools

Kubernetes

AWS

gRPC

MySQL

Snowflake

Job description

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 Merchant & Partner Lifecycle (M&PL) team is at the forefront of Affirm’s architectural transformation. We are addressing critical architectural risks by consolidating merchant lifecycle orchestration into a newly cohesive domain.
You will act as a technical leader responsible for building out the brand new lifecycle-orchestrator service that’s at the heart of multiple connected systems. Your work will deliver immediate availability improvements through system simplification and isolation, and modernize older parts of the codebase.
What You'll Do

• Design & expand the backbone of our platform to scale to hundreds of thousands of merchants from all around the world
• Design and align the scope of work with other teams to deliver cross-team projects
• Mentor other engineers to ensure their development & growth
• Partner with Engineering Manager and Team Lead to drive and execute the long-term vision of the team
• Execute technical strategy for broad or complex requirements with insightful and forward-looking approaches that go beyond the direct team and solve large open-ended problems
• Utilize agentic development tools like Claude Code to automate parts of the development process
• Improve engineering standards, tooling, and processes throughout the organization

What We Look For

• 5+ years of experience as a backend software engineer
• A strong understanding of Domain-Driven Design, distributed systems, and how architectural decisions affect performance and maintainability
• Proficiency with data models, API design (http and RPC), state machines, event-driven architecture, and database design
• Excellent communication skills, both written and verbal. Must be proficient in asynchronous communication–written tech specs, ADRs, project plans, etc.
• Experience designing, developing, and launching backend systems (our stack: AWS, gRPC, Snowflake, Kotlin, Python, MySQL, Kubernetes). Java and Kotlin experience are especially helpful.
• Prior experience with monitoring and alerting systems (sentry.io, rollbar, chronosphere, kibana)

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
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.