Staff Software Engineer

WEX Inc; India; On-site; INR 4,000,000 - 7,000,000; Full time

Job summary

WEX Inc. is seeking a Staff Backend Engineer to lead the transformation of the Digital Credit Platform, moving from a legacy monolith to a cloud-native microservices ecosystem. You will architect scalable adjudication APIs, enable AI-driven development, and drive live production support while ensuring zero-downtime migrations.

The role emphasizes API-first design, OpenAPI contracts, and collaboration with data science for real-time credit decisioning models.

Qualifications

• 10+ years of backend engineering experience in Fintech, Lending, or Credit systems.
• Experience migrating monoliths to microservices and designing scalable API ecosystems.
• Strong knowledge of Java, Spring Boot, and cloud-native architectures.

Responsibilities

• Lead decoupling of core credit logic from legacy monolith into cloud-native microservices.
• Design zero-downtime migration strategies for high-volume traffic.
• Build modular adjudication layers with versioned APIs for multi-channel access.
• Champion AI DLC practices to accelerate development and testing.
• Mentor engineers and raise code quality and observability standards.

Skills

Java 17/21

Spring Boot 3.x

Spring Cloud

Microservices

Event-Driven Architecture

Kafka/RabbitMQ

API Contracts OpenAPI/Swagger

AI DLC Tools

AWS

Leadership & Mentorship

Education

Bachelor's degree in Computer Science or related field

Tools

Cursor

GitHub Copilot

LLM-based code generation

OpenAPI/Swagger tooling

Job description

Staff Backend Engineer : Digital Credit Platform (AI-Augmented Engineering)

Domain: Fintech, Lending, or Credit Systems

About the team / Role

As a Staff SOFTWARE Engineer, you will be the primary architect and execution lead for the transformation of our Digital Credit Application. We are pivoting from a legacy monolith to a high-performance, pluggable API ecosystem. Your mission is to decouple core adjudication logic, enable rapid A/B testing of the customer journey, and lay the technical foundation for future AI-driven chat and automated decisioning experiences. This is a high-impact role designed for a true "builder" who thrives on the duality of supporting a live production environment while aggressively migrating mission-critical services to a modern, microservices-based backbone. The AI Edge: We are a forward-thinking engineering org. You are expected to be an expert in leveraging AI Software Development Lifecycle (AI DLC) tools (e.g., GitHub Copilot, Cursor, Amazon Q, LLM-based code gen and architecture agents) to accelerate migration, write bulletproof tests, and automate documentation.

How you'll make an impact

Architectural Migration & Strategy

• Strangler Fig Migration: Lead the decoupling of core credit application logic out of the legacy monolith and into a scalable, cloud-native Java/Spring Boot microservices environment.
• Migration with Zero Downtime: Design and execute high-volume traffic migration strategies from legacy systems to new stacks seamlessly without disrupting live customers.

Pluggable Adjudication & API Ecosystem

• Modular Architecture: Design and implement a modular adjudication layer allowing the business to swap or update credit rules and third-party data providers without impacting core application flows.
• API-First Design: 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 backend infrastructure for dynamic routing and experimentation, allowing real-time testing of various application flows.

AI Readiness & Process Acceleration

• AI DLC Mastery: Champion the use of AI tools across the development lifecycle to write code faster, refactor legacy code into modern Java, and generate robust test suites.
• Data Science Partnership: Partner with Data Science teams to ensure data pipelines and backend schemas are optimized for LLM integration and real-time credit decisioning models.

Operational Excellence & Leadership

• Observability & CI/CD: Establish rigorous standards for CI/CD, observability (OpenTelemetry), and automated contract testing.
• Technical Mentorship: Provide guidance to mid-level and senior engineers, fostering a culture of high engineering standards, clean code, and AI-assisted productivity.

Experience you will bring

Technical Architecture & Stack

• 10+ Years of Engineering Excellence: Proven track record in backend architecture, specifically within Fintech, Lending, or Credit systems.
• Modern Java Stack: Expert-level proficiency in Java 17/21, Spring Boot 3.x, and Spring Cloud.
• Monolith-to-Distributed Migration: Significant experience extracting tightly coupled business logic from legacy backends into external, scalable cloud microservices (AWS).
• 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 asynchronous data consistency between the new API layer and legacy systems of record during migration phases.
• Contract-First Development: Strict adherence to API contracts (OpenAPI/Swagger) to ensure seamless collaboration with frontend teams.

AI & Modern Delivery Tools

• AI DLC Proficiency: Hands-on experience using AI coding assistants (Cursor, Copilot, etc.) to optimize workflows, refactor legacy code, and accelerate delivery.

Leadership & Education

• Strong analytical skills and a proven capability in resolving complex, cross-functional problems.
• Excellent written and verbal communication skills; ability to present complex technical concepts clearly to stakeholders.

Bachelor's degree in Computer Science or a related technical field.