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Job Title


Senior Software Engineer, Backend (Merchant Interfaces)


Company : Affirm


Location : Kitchener, Region of Waterloo


Created : 2025-10-05


Job Type : Full Time


Job Description

Senior Software Engineer, Backend (Merchant Interfaces) Join to apply for the Senior Software Engineer, Backend (Merchant Interfaces) role at Affirm 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 Interface (PMI) team builds the APIs and solutions that power Affirms integrations with Enterprise Merchants and Partners. We create and manage the APIs and tools that drive checkout and merchant onboarding, and we collaborate with stakeholders to design and build custom end-to-end integrated solutions. What Youll Do With the support of your teams tech lead and manager, you will break down larger projects into individual tasks, deliver them in multiple phases, and collaborate with others to ensure timely delivery of your work. You will support your peers and stakeholders in the product development lifecycle by collaborating with product management, design & analytics by participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs. You will contribute to the entire API lifecycle, including designing, developing, testing, maintaining, and evolving our APIs. You will support the operations and availability of your teams artifacts by creating and monitoring metrics, escalating when needed, and supporting keep the lights on & on-call efforts. You will contribute to a sense of community on your team by engaging in growth and development activities such as participation in the interview process. What We Look For You have a total of 5+ years of experience as a software engineer. You have experience designing, developing and launching backend systems and are proficient in 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 Bachelors degree in a related field. 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.) CAN base pay range per year: $150,000 - $200,000 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. Benefits 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 Its 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. 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. Affirm is an equal opportunity employer and welcomes applications from diverse candidates. #J-18808-Ljbffr