Software Engineer II, Fullstack (Ads Platform)

Affirm; Oshawa; On-site; CAD 90,000 - 130,000; Full time

Job summary

Affirm is seeking a software engineer in Canada to contribute to our web apps and APIs. You will work with React-based front ends, design scalable APIs, and ship features end-to-end with a focus on reliability and clean code.

You’ll collaborate with product, design, and analytics, participate in code reviews, and grow through ongoing feedback and on-call responsibilities.

Qualifications

• 1.5+ years of software engineering experience.
• Experience shipping web apps with declarative UI like React.
• Experience designing, developing and launching APIs at scale using Python or Kotlin.
• Able to translate simple problems into well-structured, tested, extensible code.
• Skilled at navigating large codebases, debugging, and providing feedback via reviews.
• Demonstrates ownership and seeks feedback from the team.

Responsibilities

• Break down large projects into tasks, delivering in phases.
• Collaborate with product, design & analytics on ideation and decisions.
• Monitor metrics, keep artifacts running, and participate in on-call efforts.
• Contribute to team growth and interview processes.

Skills

React

API design

Python

Kotlin

Code reviews

Ownership

Job description

At Affirm, 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.

Our Marketplace is continually evolving to deliver a deeply personalized shopping experience that seamlessly links consumers with merchant partners. By leveraging machine learning alongside rich consumer and merchant data, we aim to simplify and streamline the customer journey around everyday and major purchases with tailored brands, products, deals, and offers. In tandem, we are advancing our Ads Platform which is a key technology that empowers merchant partners to strategically deploy their budgets and reach targeted consumers for maximum incremental impact.

What You'll Do

• With the support of your team’s 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 support the operations and availability of your team’s 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 1.5+ years of experience as a software engineer.
• You have experience shipping web apps using declarative UI frameworks like React.
• You have experience designing, developing and launching APIs at scale using languages like Python or Kotlin.
• 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,