Senior Software Engineer, Full Stack (Zero to One Labs)

About the role

Zero To One (ZT1) is Affirm’s 0 -> 1 innovation lab, focused on turning bold ideas into validated new businesses. Operating outside the standard Product and Engineering structure, ZT1 is built for speed, autonomy, and decisive execution. We run fast, hypothesis-driven experiments with a clear goal: prototype quickly, generate real signals, and drive explicit “kill or scale” decisions on high-impact opportunities, with AI as a core enabler across the stack.

What You'll Do

• You will be responsible for owning and delivering quarterly goals for your team, leading engineers on your team through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery.
• 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 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” & on-call efforts.
• You will foster a culture of quality and ownership on your team by setting or improving code review and design standards for your team, and advocating for them beyond your team through your 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 a total of 4+ years of experience as a software engineer.
• You are experienced in designing, developing and launching backend systems at scale technologies like Python, Kotlin, AWS, MySQL, and Kubernetes.
• You have experience shipping web apps using declarative UI frameworks like React or Vue.
• You have experience leveraging AI tools, agentic coding workflows, and automation to accelerate development, prototyping, and problem solving.
• 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.