Senior Software Engineer, Backend (Payments)

Affirm; United Kingdom; Remote; GBP 101,000 - 149,000; Full time

Benefits offered by this job

Health coverage

Tech stipends

Flexible time off

ESPP

Job summary

Affirm is a remote-first company focused on transparent pay and flexible benefits. The Consumer Payments team builds scalable systems enabling billions in transactions while maintaining reliability.

The role emphasizes backend design, APIs at scale, and collaboration with product, design and analytics. The UK remote position offers a base pay range and equity rewards, with visa sponsorship not available.

Qualifications

• 1.5+ years of experience as a software engineer.
• Experience designing, developing and launching backend systems.
• Proficient in Python or Kotlin.
• Familiar with AWS, MySQL and Kubernetes.
• Experience designing, developing and launching APIs at scale.
• Ability to work across multiple software components and write clean, well-tested code.
• Ability to navigate large code bases and contribute to code reviews.
• Strong communication and collaboration skills.

Responsibilities

• Break down projects into tasks and deliver in phases with team.
• Collaborate with product management, design and analytics across lifecycle.
• Support operations and on-call efforts and monitor metrics.
• Contribute to team growth through participation in interviews.

Skills

Backend development

Python

Kotlin

APIs

Distributed systems

Tools

AWS

MySQL

Kubernetes

Job description

Remote UK

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.

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. To make affirm the best way to pay, the Consumer Payments team works to ensure that any customer can successfully utilize their financial data and preferred payment method to transact, without harming their financial health. The systems owned by the Consumer Payments team move billions of dollars per year, this means reliability and scalability are at the heart of everything we do.

What You'll Do

• With the support of your team’s tech lead and manager, you will break down larger projects into individual tasks, deliver them in multiple phases, and collaborate with others to ensure timely delivery of your work.
• 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 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 contribute to a sense of community on your team by engaging in growth and development activities such as participation in the interview process.

What We Look For

• You have a total of 1.5+ years of experience as a software engineer.
• You have experience designing, developing and launching backend systems and are proficient in one of Python or Kotlin.
• You are familiar with the building blocks of distributed systems, and the technologies like AWS, MySQL and Kubernetes.
• You have experience designing, developing and launching APIs at scale using languages like Python or Kotlin.
• You have mastered taking a simple problem or business scenario into a solution that interacts with multiple software components, and executing on it by writing clear, easily understood, well tested and extensible code.
• You are comfortable navigating a large code base, debugging others' code, and providing feedback to other engineers through code reviews.
• 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.

Base Pay Grade - L

Equity Grade - 4

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% subsidised 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).

GBP base pay range per year: £101,000 - £149,000

Location: Remote UK

Base Pay Grade - L

Equity Grade - 4

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% subsidised 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).

GBP base pay range per year: £101,000 - £149,000

Location: Remote UK

Please note that visa sponsorship is not available for this position.

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.