Staff Backend Engineer – Fraud & Payment Risk Platform

Flex; San Francisco (CA); Hybrid; USD 200,000 - 250,000; Full time

Benefits offered by this job

Hybrid work arrangement

Relocation assistance

Job summary

Flex is seeking a Staff Software Engineer to architect and build the Fraud and Payment Risk Platform. You will own backend services, data ingestion, and ML lifecycle tooling, serving real-time and batch risk features with robust observability and scalable infrastructure.

You will collaborate with product, risk, and data science teams to deliver reusable platform capabilities, with hybrid office expectations in New York, San Francisco, and other U.S. cities.

Qualifications

• 6+ years of professional software engineering experience, building and operating backend systems.
• 5+ years of hands-on Java experience with Spring Boot.
• Experience leading architecture of complex distributed systems or shared backend platforms.
• Strong API design, service integration, data modeling, caching, and distributed-system failure handling.
• Experience diagnosing performance bottlenecks and improving scalability through measurement and testing.
• Cloud infrastructure, containerized deployments, and relational/NoSQL data stores.
• Observability, monitoring, and alerting for production systems.
• Ability to lead technical decisions across teams and mentor engineers.

Responsibilities

• Lead backend architecture and development for the Fraud and Payment Risk Platform.
• Design for scalability, performance, and reliability across services.
• Build feature ingestion, integration, and serving for real-time and batch features.
• Develop infrastructure for rules and experimentation with UAT and safe rollouts.
• Own ML lifecycle tooling: development, validation, deployment, monitoring.
• Own platform monitoring, alerting, and reliability across services.
• Improve platform extensibility for cross-team adoption.
• Drive design-to-production initiatives with cross-team coordination.
• Raise engineering bar via reviews, testing, and deployment safety.

Skills

Java

Spring Boot

Distributed systems

API design

Cloud (AWS)

Observability

Leadership

Tools

Terraform

GitHub Actions

Datadog

Snowflake

EKS

Aurora

DynamoDB

Job description

Flex is seeking a Staff Software Engineer to architect and build the Fraud and Payment Risk Platform. You will own backend services, data ingestion, and ML lifecycle tooling, serving real-time and batch risk features with robust observability and scalable infrastructure.

You will collaborate with product, risk, and data science teams to deliver reusable platform capabilities, with hybrid office expectations in New York, San Francisco, and other U.S. cities.