Staff Software Development Engineer

WEX is a financial technology company, and they are seeking a Staff Backend Engineer to lead the architectural migration of their Digital Credit Application. The role involves designing a modular adjudication layer, building robust APIs, and ensuring operational excellence while providing mentorship to other engineers.

Responsibilities:

• Architectural Migration: Lead the "Strangler Fig" migration of credit application logic out of Salesforce and into a scalable, cloud-native Java/Spring Boot microservices environment
• Pluggable Adjudication: Design and implement a modular adjudication layer that allows the business to swap or update credit rules and third-party data providers without impacting the core application flow
• API-First Ecosystem: Build and maintain robust, versioned REST/gRPC APIs that support a multi-channel experience (Mobile, Web, and future AI Chat interfaces)
• A/B Strategy Enablement: Engineer the backend infrastructure to support dynamic routing and experimentation, allowing Product teams to test various application flows and UI treatments in real-time
• Operational Excellence & Ownership: Transition the platform by establishing rigorous standards for CI/CD, observability (OpenTelemetry), and automated testing
• AI Readiness: Partner with Data Science teams to ensure data pipelines and backend schemas are optimized for LLM integration and real-time credit decisioning models
• Provide technical mentorship and guidance to mid-level and senior engineers, fostering a culture of high engineering standards

Requirements:

• 10+ Years of Engineering Excellence: Proven track record in backend architecture, specifically within Fintech, Lending, or Credit systems
• Salesforce Integration Mastery: Significant experience integrating Salesforce with external AWS/Cloud microservices. You understand how to extract business logic from Apex/Flows into external services
• Modern Java Stack: Expert-level proficiency in Java 17/21, Spring Boot 3.x, and Spring Cloud
• Complex Adjudication & Rules Engines: Experience building or implementing rules engines (e.g., Drools, Camunda, or custom JSON-logic) for automated decisioning
• Event-Driven Design: Deep experience with Kafka or RabbitMQ for maintaining data consistency between the new API layer and legacy systems of record
• Contract-First Development: Strong belief in API contracts (OpenAPI/Swagger) to ensure seamless collaboration with frontend and mobile teams
• Migration Strategy: Demonstrated ability to migrate high-volume traffic from legacy systems to new stacks with zero downtime
• Excellent analytical skills and capability in identifying and resolving complex, cross-functional problems
• Strong written and verbal communication skills, able to present complex technical concepts clearly
• Bachelor's degree in Computer Science or a related field