Senior Software Engineer, Back-end (Fraud)

Posted Yesterday
Easy Apply
Be an Early Applicant
Hiring Remotely in Spain
Remote
86K-122K Annually
Senior level
Big Data • Fintech • Mobile • Payments • Financial Services
We create honest financial products that improve lives. Ready to make a difference?
The Role
Lead design and delivery of real-time fraud decisioning services and APIs, extend decisioning platform to international markets, integrate regional risk vendors and ML/AI signals, own platform tooling and availability, mentor engineers, collaborate cross-functionally, and participate in on-call rotation.
Summary Generated by Built In

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.

The Fraud Engineering organization builds the foundational and tactical software that enables Affirm to respond strategically to fraud - both in real time and after the transaction. Our mission is to support business growth while protecting Affirm, our buyers, and our merchants. We evaluate risk at critical decision points in the user journey, rapidly adapt to evolving fraud patterns, and equip operations teams with the tools needed to investigate and mitigate fraud at scale.

We’re looking for a Senior Software Engineer to join our fully remote team based in Europe. You’ll collaborate closely with stakeholders across North America - including teams in Product, Compliance, Machine Learning, Fraud Operations, Fraud Strategy, and other Fraud Engineering teams.

The Fraud Engineering organization builds the foundational and tactical software that enables Affirm to respond strategically to fraud - both in real time and after the transaction. Our mission is to support business growth while protecting Affirm, our customers, and our merchants. We evaluate risk at critical decision points in the user journey, rapidly adapt to evolving fraud patterns, and equip operations teams with the tools needed to investigate and mitigate fraud at scale. 

The Fraud International Team (FIT) leads the engineering effort to extend Affirm's Fraud Decisioning System into markets beyond the US - Canada, the UK, Australia, and growing rapidly. We own real-time fraud decisioning for these markets, integrate region-specific risk vendors, and are building the platform that lets Affirm stand up fraud protection in a new country quickly and safely. As Affirm expands globally, FIT scales with it. 

We're looking for a Senior Software Engineer to join our fully remote team based in Europe. You'll collaborate closely with stakeholders across North America - including teams in Product, Compliance, Machine Learning, Fraud Operations, Fraud Strategy, and other Fraud Engineering teams.

What You'll Do
  • You will own and deliver quarterly goals for your team, leading engineers through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery.
  • You will design and implement real-time fraud decisioning services and APIs in Python or Kotlin, extending Affirm's Fraud Decisioning System to markets beyond the US.
  • You will build and evolve the platform and tooling that let Affirm launch fraud decisioning in a new country quickly—turning market-by-market setup (rules, models, and vendor configuration) into a repeatable, low-friction path so launches scale sub-linearly with the number of markets.
  • You will integrate region-specific fraud and risk vendors and help operationalize the machine learning and AI signals that power real-time decisioning, while using modern AI tooling to move faster as an engineer.
  • You will support peers and stakeholders across the product development lifecycle - collaborating with Product, Machine Learning, Analytics, and Fraud Strategy, articulating technical constraints, and partnering on decisions that properly weigh risks and trade-offs.
  • You will support the operations and availability of your team's systems by creating and monitoring metrics, escalating when needed, and contributing to keep-the-lights-on and on-call efforts.
  • You will foster a culture of quality and ownership - setting and improving code review and design standards, mentoring teammates, and leading by example.
  • On-Call Rotation - There would be an on-call rotation for this role as a requirement.
What We Look For
  • 5+ years of experience building backend systems at scale using Python or Kotlin. 
  • Experience with distributed systems and infrastructure using AWS, MySQL/PostgreSQL, and Kubernetes.
  • Strong system design skills and a track record of delivering maintainable, extensible services.
  • Fluency with AI-driven engineering - every Affirm engineer builds with tools like Claude Code and most PRs are co-authored with AI, so directing and orchestrating AI and excelling in the reviewer's seat (setting intent, critically evaluating generated code, and owning its correctness, quality, and security) is a core expectation.
  • Proficiency in SQL and working with data-rich environments.
  • Familiarity with CI/CD practices and safe production deployments.
  • Strong written and verbal communication skills, especially in distributed teams.
  • A proactive, ownership-driven mindset with a focus on learning and team success.
  • Experience with Snowflake, dbt, Airflow, or Chronosphere (nice to have)
  • Background in fraud prevention, risk systems, or real-time decisioning (nice to have)
  • Experience building for multiple markets or regions - internationalization or localization (nice to have)
  • Experience working in the fintech sector or other highly regulated environments, with a strong understanding of risk, compliance, and operational constraints. (nice to have)
Compensation & Benefits

Base Pay Grade - N

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% 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).

ESP base pay range per year: €86,000  -  €122,000    

Additional benefits include:

  • Flexible Spending Wallets for tech, food and lifestyle
  • Away Days - wellness days to take off work and recharge
  • Learning & Development programs
  • Parental benefits
  • Employee Resource & Community Groups

We are able to offer visa sponsorship for this role, but do require that someone is based in Spain for the role.

Location - Remote Spain

#LI-Remote

Affirm is proud to be a remote-first company! The majority of our roles are remote and you can work almost anywhere within the country of employment. Affirmers in proximal roles have the flexibility to work remotely, but will occasionally be required to work out of their assigned Affirm office. A limited number of roles remain office-based due to the nature of their job responsibilities.

We’re extremely proud to offer competitive benefits that are anchored to our core value of people come first. Some key highlights of our benefits package include: 

  • Health care coverage - Affirm covers all premiums for all levels of coverage for you and your dependents 
  • Flexible Spending Wallets - generous stipends for spending on Technology, Food, various Lifestyle needs, and family forming expenses
  • Time off - competitive vacation and holiday schedules allowing you to take time off to rest and recharge
  • ESPP - An employee stock purchase plan enabling you to buy shares of Affirm at a discount

We believe It’s On Us to provide an inclusive interview experience for all, including people with disabilities. We are happy to provide reasonable accommodations to candidates in need of individualized support during the hiring process.

[For U.S. positions that could be performed in Los Angeles or San Francisco] Pursuant to the San Francisco Fair Chance Ordinance and Los Angeles Fair Chance Initiative for Hiring Ordinance, Affirm will consider for employment qualified applicants with arrest and conviction records.

By clicking "Submit Application," you acknowledge that you have read Affirm's Global Candidate Privacy Notice and hereby freely and unambiguously give informed consent to the collection, processing, use, and storage of your personal information as described therein.

Skills Required

  • 5+ years building backend systems at scale using Python or Kotlin
  • Experience with distributed systems and infrastructure using AWS, MySQL/PostgreSQL, and Kubernetes
  • Strong system design skills and track record delivering maintainable, extensible services
  • Fluency with AI-driven engineering and ability to evaluate and own AI-assisted code (e.g., Claude Code)
  • Proficiency in SQL and working with data-rich environments
  • Familiarity with CI/CD practices and safe production deployments
  • Strong written and verbal communication skills for distributed teams
  • Proactive, ownership-driven mindset with focus on team success
  • Participation in on-call rotation and supporting system availability
  • Must be based in Spain (role location requirement); visa sponsorship available
  • Experience with Snowflake, dbt, Airflow, or Chronosphere
  • Background in fraud prevention, risk systems, or real-time decisioning
  • Experience building for multiple markets or internationalization/localization
  • Experience in fintech or regulated environments with understanding of risk and compliance

What the Team is Saying

Nupur
Jerry
Adam
Affirm
Affirm
Affirm

Affirm Compensation & Benefits Highlights

  • Healthcare Strength Benefits include comprehensive medical, dental, vision, and robust mental‑health programs, with $0 employee medical premiums for certain plans. Feedback suggests this combination makes coverage both strong and cost‑effective.
  • Parental & Family Support Birth and non‑birth parents receive 18 weeks of fully paid leave plus a four‑week, full‑pay return‑to‑work transition, alongside family‑planning support. Feedback suggests these policies are a standout strength for those planning or growing families.
  • Leave & Time Off Breadth Generous/flexible PTO is augmented by 20 company‑wide Away Days and additional options like “Life Happens Leave.” Feedback suggests the mix enables both collective recharge and personal time away.

Affirm Insights

Am I A Good Fit?
beta
Get Personalized Job Insights.
Our AI-powered fit analysis compares your resume with a job listing so you know if your skills & experience align.

The Company
HQ: San Francisco , CA
2,200 Employees
Year Founded: 2012

What We Do

At Affirm, we help people say yes to the things that matter with flexible, transparent ways to pay over time. No hidden fees, no compound interest, and no fine print—just a smarter way to spend.

Why Work With Us

Who is an Affirmer? /noun/ Someone who believes finance shouldn’t be complicated. We come from a diverse set of backgrounds and we’re driven by the desire to improve lives through honest financial products. We define success by challenging one another to bring our best ideas to every single project—and we have fun while doing it.

Gallery

Gallery
Gallery
Gallery
Gallery
Gallery
Gallery
Gallery

Affirm Offices

Remote Workspace

Employees work remotely.

Affirm is a remote-first company! Our employees can work anywhere in the U.S. but if an office is more your style, we have office locations in San Francisco, Chicago, New York City, and Pittsburgh.

Typical time on-site:
HQSan Francisco, CA
Spain
United Kingdom
Chicago, IL
New York, NY
Toronto, ON
Warsaw, PL
Learn more

Similar Jobs

Affirm Logo Affirm

Senior Software Engineer

Big Data • Fintech • Mobile • Payments • Financial Services
Easy Apply
Remote
Spain
2200 Employees
85K-115K Annually

Affirm Logo Affirm

Senior Software Engineer

Big Data • Fintech • Mobile • Payments • Financial Services
Easy Apply
Remote
Spain
2200 Employees
85K-115K Annually

Affirm Logo Affirm

Senior Software Engineer

Big Data • Fintech • Mobile • Payments • Financial Services
Easy Apply
Remote
Spain
2200 Employees
86K-122K Annually

Affirm Logo Affirm

Senior Software Engineer

Big Data • Fintech • Mobile • Payments • Financial Services
Easy Apply
Remote
Spain
2200 Employees
86K-122K Annually

Sign up now Access later

Create Free Account

Please log in or sign up to report this job.

Create Free Account