Senior Software Engineer, Backend (Comms Core)

About the Engineering Team

The Engineering team builds systems that power Affirm's mission. We take pride in our craft, building reliable, performant, and scalable solutions that touch every part of the business. Whether we're enabling new ways to pay, ensuring our platforms can scale to the most demanding levels in the industry, or developing seamless servicing experiences, our focus is on solving complex problems through exceptional engineering.

About the Team

Affirm's Communications team builds and modernizes the highly available platform that delivers billions of customer messages reliably and on time across the customer journey. As a senior backend engineer, you will shape multi-region, multi-tenant infrastructure, APIs, and vendor integrations that help product teams communicate with customers at scale.

What You'll Do

• Own and deliver quarterly technical goals for the Communications area, collaborating with teammates to solve ambiguous, open-ended problems across messaging infrastructure.
• Design and evolve reliable backend services for high-volume communications across multi-region, multi-tenant environments, including orchestration, delivery, preferences, templates, and observability.
• Collaborate with product management, design, analytics, security, and engineering partners throughout the product lifecycle, articulating technical constraints and balancing customer impact, risks, and trade-offs.
• Design, implement, and operate resilient integrations with external messaging vendors, balancing reliability, latency, cost, and compliance.
• Proactively identify and solve project, process, technology, or business issues that affect scalability, developer experience, and operational resilience.
• Support the operations and availability of your team's services by defining service-level objectives and metrics, improving alerting and incident response, and participating in on-call efforts.
• Foster quality and ownership by improving design, testing, code review, rollout, and operational standards, and advocating for them through writing and tech talks.
• Help develop talent on your team by providing feedback, mentorship, and technical direction, and leading by example.

On-Call Rotation: An on-call rotation is a requirement for this role.

What We Look For

• 5+ years of experience in software development or engineering, with a deep understanding of system design and architecture.
• Proficiency in modern programming languages such as Python, Kotlin, or similar.
• A track record of developing highly available distributed systems using technologies like AWS, MySQL, DynamoDB, and Kubernetes.
• Experience designing multi-region, multi-tenant platforms with strong isolation, scalability, failure recovery, and data-consistency guarantees.
• Experience integrating with third-party communications or messaging vendors and designing abstractions that account for different capabilities, rate limits, and failure modes.
• Experience defining a technical plan for the delivery of a significant feature or system component with an elegant, simple and extensible design.
• You write high quality code that is easily understood and used by others.
• Proficiency at making significant changes in a large code base, with a suite of tools and practices that enable you and your team to do so safely.
• Proficiency with AI-assisted development tools and sound judgment in validating their outputs.
• Ownership of your growth, proactively seeking feedback from your team, your manager, and your stakeholders.
• Strong verbal and written communication skills that support effective collaboration with our global engineering team.

Total Rewards

Rewards combine base pay, equity (from parent company), and comprehensive benefits.

• Base pay (Grade N): 308,000 zł - 428,000 zł. New employees typically start at the beginning of the range. Pay is based on factors including location, experience, and job-related skills.
• Equity (Grade 4, awarded in US Dollars): New hire equity of $32,000-$48,000; annual refresh of $10,000; reward equity of $0-$150,000.
• Flexible spending wallets for technology and wellbeing, reimbursable up to 1390 zł per month.

Benefits

• Competitive paid time off, paid public holidays, and additional paid Away Days.
• Comprehensive private healthcare through Lux Med's Platinum package.
• A MultiSport card.
• Learning and development programs.
• Family healthcare support through Maven and parental leave support through Parentaly.
• Mental well-being support through Lyra, including up to 12 confidential counseling or coaching sessions each year for you and your household members.
• Financial well-being support through Northstar, with unlimited access to Certified Financial Advisors and planning tools at no cost.
• Employee Resource Groups (ERGs).
• Eligibility for creative tax benefits, subject to applicable law, role, and company policy.
• Employee stock purchase plan (ESPP) to buy Affirm stock at a discount.
• 100% subsidized medical, dental and vision coverage for you and your dependents.

Location

Remote, Poland. Affirm is remote-first; most roles can be located anywhere in Poland. Some positions may occasionally require in-person work, and all new hires will be invited to an in-person onboarding experience.