Staff Engineer

Posted 10 Hours Ago
Hiring Remotely in US
Remote
141K-173K Annually
Expert/Leader
Fintech • Payments
The Role
Lead the migration of a legacy digital credit application monolith to a cloud-native Java and Spring Boot microservices ecosystem. Design modular adjudication services, versioned REST and gRPC APIs, event-driven integrations, zero-downtime migration strategies, and A/B testing infrastructure. Drive AI-assisted development, observability, CI/CD, contract testing, Salesforce synchronization, and collaboration with data science teams. Mentor engineers and provide technical leadership across complex fintech, lending, and credit systems.
Summary Generated by Built In

About the team / Role:

As a Staff Software Engineer, you will be the primary architect and execution lead for leading the platform changes for the 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. You will encounter varied customer scenarios where your out-of-the-box approach is a better fit than standard industry practices. We expect you to make a true difference for the customer, leveraging technology and AI to best serve and solve for good.


The AI Edge: We are a forward-thinking engineering org. You are expected to be an expert in leveraging AI Software Development Lifecycle (ADLC) 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 micro services environment.
  • Migration with Zero Downtime: Design and execute high-volume traffic migration strategies from legacy systems to new stacks seamlessly without disrupting live customers.
  • Salesforce Proficiency: A significant portion of existing systems is embedded within various Salesforce capabilities throughout the application lifecycle. Proficiency in Salesforce is a strong advantage, as different integrations will require the new stack to support bidirectional data and state synchronization within the Salesforce ecosystem.

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.
The base pay range represents the anticipated low and high end of the pay range for this position. Actual pay rates will vary and will be based on various factors, such as your qualifications, skills, competencies, and proficiency for the role. Base pay is one component of WEX's total compensation package. Most sales positions are eligible for commission under the terms of an applicable plan. Non-sales roles are typically eligible for a quarterly or annual bonus based on their role and applicable plan. WEX's comprehensive and market competitive benefits are designed to support your personal and professional well-being. Benefits include health, dental and vision insurances, retirement savings plan, paid time off, health savings account, flexible spending accounts, life insurance, disability insurance, tuition reimbursement, and more. For more information, check out the "About Us" section.Pay Range: $140,600.00 - $173,100.00

Skills Required

  • 10+ years of engineering experience, specifically in backend architecture
  • Experience in fintech, lending, or credit systems
  • Expert proficiency with Java 17 or 21, Spring Boot 3.x, and Spring Cloud
  • Significant experience migrating monolithic backends to scalable AWS cloud microservices
  • Experience building or implementing rules engines such as Drools, Camunda, or custom JSON-Logic
  • Deep experience with Kafka or RabbitMQ for event-driven data consistency
  • Experience with contract-first API development using OpenAPI or Swagger
  • Hands-on experience using AI coding assistants such as Cursor or GitHub Copilot
  • Strong analytical, written, verbal, and cross-functional communication skills
  • Bachelor's degree in Computer Science or a related technical field
  • Salesforce proficiency and experience supporting bidirectional data and state synchronization

WEX Inc. Compensation & Benefits Highlights

The following summarizes recurring compensation and benefits themes identified from responses generated by popular LLMs to common candidate questions about WEX Inc. and has not been reviewed or approved by WEX Inc..

  • Leave & Time Off Breadth — Leave offerings are portrayed as a standout, with generous PTO and additional paid time for volunteering. Time-off flexibility is also positioned as a meaningful part of the overall rewards experience.
  • Retirement Support — Retirement benefits are presented as strong, including a 401(k) match that is described as competitive. This element appears to materially strengthen the total rewards package even when cash compensation feels less compelling.
  • Strong & Reliable Incentives — Variable compensation is sometimes framed positively through bonuses and uncapped earning potential in sales-oriented roles. Stock options are also cited as an additional reward component that can improve perceived total compensation.

WEX Inc. Insights

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The Company
HQ: Portland, ME
4,900 Employees
Year Founded: 1983

What We Do

We simplify complex payment systems for fleets, corporate payments, and healthcare—unlocking insights, opportunities, and efficiencies to give you greater control of your business. Powered by the belief that complex payment systems can be made simple, WEX (NYSE: WEX) is a leading financial technology service provider across a wide spectrum of sectors, including fleet, travel and healthcare. WEX operates in more than 10 countries and in more than 20 currencies through approximately 4,900 associates around the world. WEX fleet cards offer approximately 14 million vehicles exceptional payment security and control; our travel and corporate solutions business processes over $35 billion of purchase volume annually; and the WEX Health financial technology platform helps 343,000 employers and more than 28 million consumers better manage healthcare expenses.

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