Senior Software Engineer, Backend (Comms Core)

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.

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

• You will own and deliver quarterly technical goals for the Communications area, collaborating with teammates to solve ambiguous, open-ended problems across messaging infrastructure.

• You will design and evolve reliable backend services for high-volume communications across multi-region, multi-tenant environments, including orchestration, delivery, preferences, templates, and observability.

• You will 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.

• You will design, implement, and operate resilient integrations with external messaging vendors, balancing reliability, latency, cost, and compliance.

• You will proactively identify and solve project, process, technology, or business issues that affect scalability, developer experience, and operational resilience.

• You will 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.

• You will foster quality and ownership by improving design, testing, code review, rollout, and operational standards, and advocating for them through writing and tech talks.

• You will help develop talent on your team by providing feedback, mentorship, and technical direction, and leading by example.

• On-Call Rotation - There would be an on-call rotation for this role as a requirement.

What we look for

• You have 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.

• You have a track record of developing highly available distributed systems using technologies like AWS, MySQL, DynamoDB, and Kubernetes.

• You have experience designing multi-region, multi-tenant platforms with strong isolation, scalability, failure recovery, and data-consistency guarantees.

• You have experience integrating with third-party communications or messaging vendors and designing abstractions that account for different capabilities, rate limits, and failure modes.

• You have 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.

• You are proficient at making significant changes in a large code base, and have developed a suite of tools and practices that enable you and your team to do so safely.

• You are proficient with AI-assisted development tools and apply sound judgment to validate their outputs.

• 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.

Total rewards

We believe the people building honest financial products at Affirm should share in its success. That's why our total rewards are designed to support your health, growth, financial well-being, and future.

In service of our mission, we reward employees through a combination of base pay, equity (from parent company), and comprehensive benefits.

Base Pay Grade - N

308,000 zł  -  428,000 zł

Employees new to Affirm typically come in at the start of the pay range. 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 monthly stipends for health, wellness and tech spending, and benefits (including 100% subsidized medical coverage, dental and vision for you and your dependents). In addition, the employees may be eligible for equity rewards offered by Affirm Holdings, Inc. (parent company).

Base pay ranges and placement within those ranges are determined based on several factors, including role, experience, and job-related skills.

In addition to base pay, all employees in this role are eligible to receive equity from the parent company each year. This means as Affirm’s parent company grows, employees have the opportunity to share in that growth financially.

Equity Grade - 4 (awarded in US Dollars)

Affirm Holdings, Inc. Equity Grade example

Equity grade: 4
New hire equity: $32,000-$48,000
Annual Refresh: $10,000
Reward equity: $0-$150,000

Affirm also provides flexible spending wallets to all employees for technology and wellbeing related needs, which are reimbursable up to 1390 zł per month.

In addition to your compensation, our comprehensive benefits are designed to support you and the people who matter most. Benefits include:

• Competitive paid time off, paid public holidays, and additional paid Away Days to rest and recharge.

• Comprehensive private healthcare through Lux Med's Platinum package.

• A MultiSport card to support your health and well-being.

• Learning and development programs to help you grow professionally.

• 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 to you.

• Employee Resource Groups (ERGs) that foster connection and inclusion.

• Eligibility for creative tax benefits, subject to applicable law, role, and company policy.

Location - Remote Poland

The majority of our roles can be located anywhere in Poland.

**This job description is not a contractual document, and is not intended to have binding force.**

#LI-Remote

Remote-first with flexibility built in
Affirm is proud to be a remote-first company. Most roles can be done from almost anywhere within the country of employment. Some positions may occasionally require in-person work at an Affirm office, and a few are office-based due to the nature of the work. All new hires will be invited to attend an in-person onboarding experience.

Benefits designed for you
Our benefits reflect our commitment to care, transparency, and flexibility. Here are a few highlights:

• Health coverage at no cost: We cover 100% of premiums for employees and their dependents.

• Spending stipends: Monthly stipends support your tech setup, and the ability to choose health and wellness options that are right for you.

• Time off to recharge: Flexible time off and generous holiday calendars help you rest when you need to.

• Own a piece of what you build: Our employee stock purchase plan (ESPP) lets you buy Affirm stock at a discount.

We’re committed to providing an inclusive interview process, including accommodations for candidates with disabilities. If you need support, we’re happy to help.

For positions based in San Francisco or Los Angeles: Affirm considers qualified applicants with arrest and conviction records, as required by law.

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