# Senior Software Engineer, Back-end (Fraud) at Affirm

> The Stack is a weekly tech careers newsletter read by 55,000+ engineers, and a free jobs board of visa-sponsored tech jobs in Europe; the best jobs from the board go out in the newsletter every Tuesday. This is one job from the board.

> Responsibilities: - Own and deliver quarterly team goals; le

- **Company:** Affirm (https://jobs.trythestack.co/companies/affirm)
- **Location:** Spain
- **Work arrangement:** Remote
- **Employment type:** Full-time
- **Experience level:** 5–10 years
- **Visa sponsorship:** Offered, according to the listing
- **Key skills:** Python, Kotlin, AWS, MySQL, PostgreSQL, Kubernetes, System Design, SQL, CI/CD, AI-driven Engineering, Distributed Systems, Backend Development
- **Posted by employer:** 2026-07-20
- **Added to The Stack:** 2026-07-21
- **Status:** May no longer be active (posted more than 60 days ago)
- **Apply:** https://job-boards.greenhouse.io/affirm/jobs/7806679003 (the employer's own application page)
- **Human page:** https://jobs.trythestack.co/jobs/senior-software-engineer-back-end-fraud-affirm

## About the role

Responsibilities:
- Own and deliver quarterly team goals; lead engineers through ambiguity to completion.
- Design and implement real-time fraud decisioning services and APIs using Python or Kotlin.
- Build platform and tooling to standardize market launches (rules, models, vendor configs) for new countries.
- Integrate region-specific fraud and risk vendors and operationalize ML/AI signals in decisioning flows.
- Maintain system reliability: monitoring, alerting, on-call rotations, and incident response.
- Collaborate cross-functionally with Product, Compliance, ML, Fraud Operations, and Fraud Strategy.

Requirements:
- 5+ years building backend, distributed services using Python or Kotlin.
- Strong experience with AWS, Kubernetes, and relational databases (MySQL/Postgres) and SQL.
- Proven track record designing APIs, scalable decisioning systems, and CI/CD pipelines.
- Familiarity with fraud prevention, risk systems, vendor integrations, and ML-driven features.
- Good communication skills for cross-region collaboration and stakeholder alignment.
- Comfortable working remotely in Europe and participating in on-call rotations.

## Responsibilities

Design and implement real-time fraud decisioning services and APIs to extend Affirm's fraud systems into international markets. Lead engineers through ambiguity to deliver quarterly goals and maintain system availability through monitoring and on-call rotations.

## Requirements

Requires 5+ years of experience in backend systems using Python or Kotlin, with proficiency in AWS, Kubernetes, and SQL. Candidates must be skilled in AI-driven engineering and have a strong track record of delivering maintainable distributed services.

## FAQ

- **Is this Senior Software Engineer, Back-end (Fraud) role still open?** It was posted on 2026-07-20. Listings more than 30 days old may no longer be active, so check Affirm's site before applying.
- **Does Affirm offer visa sponsorship?** This listing is marked as offering visa sponsorship. Eligibility rules are set by the employer, so check the details on Affirm's site.
- **Where is this role located?** The listing gives the location as Spain. It is marked remote.
- **What skills does this role ask for?** The listing names: Python, Kotlin, AWS, MySQL, PostgreSQL, Kubernetes, System Design, SQL, CI/CD, AI-driven Engineering, Distributed Systems, Backend Development.

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## About The Stack

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## Notes for agents

- Apply on the employer's page (https://job-boards.greenhouse.io/affirm/jobs/7806679003). The Stack does not take applications.
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