Senior Software Engineer, Back-end (Fraud)
Core
Building foundational and tactical software for real-time and post-transaction fraud decisioning to protect Affirm, buyers, and merchants while supporting business growth.
Role type
Senior Software Engineer (Back-end, Fraud)
Builds
Real-time fraud decisioning services, APIs, and a platform for rapid international expansion of fraud protection.
Domain
Fintech / Fraud Prevention / Real-time Risk Systems
Deliverable
production ML models | product features | infrastructure
Required skills
Python, Kotlin, distributed systems, AWS, MySQL/PostgreSQL, Kubernetes, system design, SQL, CI/CD, AI-driven engineering (orchestration and code review)
Preferred skills
Snowflake, dbt, Airflow, Chronosphere, fraud prevention background, internationalization experience, fintech sector experience
Technologies
Python, Kotlin, AWS, MySQL, PostgreSQL, Kubernetes, Snowflake, dbt, Airflow, Chronosphere, Claude Code
Responsibilities
Design and implement real-time fraud decisioning services and APIs; build and evolve platform tooling for rapid market launches; integrate region-specific fraud vendors; support system operations and on-call rotation; mentor teammates and set code review standards.
Seniority
Senior, hands-on IC with leadership responsibilities
