Senior Software Engineer, Fullstack (Repayments UX)

Company: Affirm

Locations: Poland; Spain

Salary: PLN 308K – PLN 428K a year

Work arrangement: Remote possible

Employment type: Full-time

Experience: 2-5 years

Posted: 2026-10-27

Responsibilities

You will lead engineering efforts to deliver quarterly goals while mentoring team members and ensuring high-quality code standards. Additionally, you will collaborate with product, design, and analytics teams to solve complex problems and maintain system availability.

Requirements

The role requires 4+ years of experience in mobile and web application development using declarative UI frameworks like React Native, React, or Vue. Proficiency in backend development with Python or Kotlin is also essential, along with strong communication and leadership skills.

Skills

  • Full-stack development
  • React Native
  • React
  • Vue
  • Python
  • Kotlin
  • Mobile application architecture
  • Backend systems design
  • Declarative UI frameworks
  • Agile methodology
  • Code review
  • Technical leadership
  • System design
  • API development
  • Performance monitoring

Benefits

  • Private healthcare
  • MultiSport card
  • Learning and development programs
  • Parental leave support
  • Mental well-being support
  • Financial well-being support
  • Employee stock purchase plan
  • Paid time off
  • Paid public holidays
  • Monthly tech and wellness stipends

About this role

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.
The Repayment UX Engineering team is growing, and we're looking for a Senior Full-Stack Software Engineer. We're a full-stack team located entirely in Europe within the same time zone, but culturally rooted in Silicon Valley. We directly improve the financial lives of over 20 million people. We build and own user journeys that enable them to pay back loans worth collectively over $40B each year. Our team exists to make these moments the most reliable and transparent in world-class consumer finance.

Our work is agile and fast-paced and we rigorously measure the impact it has on the behavior of our users. This role rewards curiosity, ownership, and a builder's mindset. You'll know exactly what your objectives are, you'll have what you need to hit them, and you'll choose your own path to get there. You'll learn quickly from experienced teammates and grow your craft on problems that matter at scale.

If you want to build something new and operate it at scale – come join us!

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 4+ years of experience of developing and architecting mobile applications, preferably using declarative UI frameworks like React Native.
You have experience shipping web apps using declarative UI frameworks like React or Vue.
You have experience designing, developing and launching backend systems and are proficient in one of Python or Kotlin.
Experience developing and architecting mobile applications, preferably using declarative UI frameworks like React Native is a bonus.
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.
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.
Emp...

About Affirm

Financial Services · 1,001-5,000 employees · headquartered in San Francisco, California · founded 2012

See all my matches — 2 min, free

More Software Engineer Jobs

456 new Software Engineer jobs were posted this week.

All Remote Software Engineer Jobs →

Get new Software Engineer jobs by email — start free

Other Jobs in Poland

Before you apply, check your resume against ATS filters for free.