Senior Software Engineer, Fullstack (Consumer Engineering)

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. Consumer Growth Experience Engineering (CGX) builds the platforms and end-to-end experiences that power Affirm’s consumer growth across push, email, app, and web. We own the core engagement surfaces and systems that help customers discover value, onboard seamlessly, and take confident next steps by using personalization, segmentation, and experimentation to deliver the right experience at the right moment.

Our work sits at the intersection of product, analytics, design, platform, and growth. We focus on building scalable, reliable tooling and consumer experiences that enable rapid go-to-market, improve conversion and activation, and grow long-term customer value. If you’re excited about shaping high-impact consumer journeys, solving ambiguous growth problems, and turning strategy into measurable outcomes at scale, CGX is the team for you.

What You'Ll Do

You will be responsible for owning and delivering quarterly goals for your team, leading engineers through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery. You will support peers and stakeholders in the product development lifecycle by collaborating with product management, design, and analytics, participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs. You will proactively identify project, process, technology, or business issues, advocate for them, and lead in solving them.

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” and on-call efforts. You will foster a culture of quality and ownership by setting or improving code review and design standards for your team, and advocating for them beyond your team through writing and tech talks. You will help develop talent on your team by providing feedback and guidance, and leading by example.

What We Look For You have experience leading significant mobile initiatives (React Native or native), including defining architecture, coordinating cross-functional launches, and maintaining high reliability in production environments. You have experience working across the React Native and native boundaries (Swift/Kotlin), debugging platform-specific issues and improving developer tooling, CI/CD, and release processes for mobile apps. You have experience implementing experimentation, feature flagging, and analytics instrumentation in mobile applications, ensuring safe rollouts and measurable impact.

You have experience shipping web apps using declarative UI frameworks like React or Vue. You are proficient in working with JavaScript/TypeScript. You have a total of 4+ years of experience as a software engineer.

You are experienced in designing, developing, and launching backend systems at scale using technologies like Python, Kotlin, AWS, MySQL, and Kubernetes. You have experience defining a technical plan for the delivery of a significant feature or system component with an elegant, simple, and extensible design, and you write high-quality code that is easily understood and used by others. You are proficient at making significant changes in a large codebase and have developed a suite of tools and practices that enable you and your team to do so safely.

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 a global engineering team. This position requires either equivalent practical experience or a Bachelor’s degree in a related field.