Senior Full-Stack Engineer (Java / Spring Boot)

This is a remote position; however, the candidate must reside within 30 miles of one of the following locations: Boston, MA; San Francisco Bay Area, CA; Dallas, TX; Salt Lake City, UT; Seattle, WA; and Portland, ME About the Team/Role We are seeking a Full-stack Senior Software Engineer with deep expertise in backend development to contribute to the WEX Beyond Fuel and Expense Management initiative within WEX Mobility Engineering. This is a brand-new initiative, offering the opportunity to shape the architecture, establish engineering practices, and build the product from initial design through production launch. You will work across web & mobile applications, backend services, APIs, and partner integrations to deliver secure, reliable, and scalable payment and expense management experiences.

Responsibilities

• This is an individual contributor role focused on delivering core capabilities while collaborating with Product, Design, Security, and engineering teams across the United States and India. ​ How you’ll make an impact: Contribute to the technical architecture, design, and implementation of the Beyond Fuel and Expense Management platform.
• Build full-stack capabilities spanning user interfaces, backend services, data models, and external integrations.
• Translate product requirements into technical designs, delivery milestones, and implementation plans.
• Design reusable business capabilities and APIs that support web, mobile, and partner experiences.
• Establish patterns for payment workflows, expense capture, approvals, spend controls, transaction reporting, and reconciliation.
• Evaluate technical options and communicate tradeoffs involving performance, security, reliability, cost, and delivery timelines.
• Write production code, review contributions, and resolve complex issues across the application stack.
• Participate in design reviews, code reviews, and technical discussions to support engineering quality.
• Establish standards for automated testing, API contracts, observability, accessibility, and secure development.
• Build production readiness into the product through actionable logs, distributed tracing, metrics, dashboards, and alerts.
• Use approved AI tools throughout development, testing, and documentation, and review and validate all generated output.
• Partner with engineering leaders to identify dependencies, manage technical risks, and support delivery.
• Own technical outcomes from initial implementation through deployment, operation, and continuous improvement.

Requirements

• Bachelor's degree in Computer Science, Software Engineering, or a related field.
• 6–8 years of professional software engineering experience.
• Strong proficiency in Java and Spring Boot, or comparable backend technologies.
• Strong understanding of object-oriented design, data structures, algorithms, and software design principles.
• Experience designing REST APIs, distributed systems, relational data models, and event-driven integrations.
• Experience with cloud platforms, preferably AWS, and automated CI/CD pipelines.
• Knowledge of authentication, authorization, data protection, and secure API design.
• Experience with unit, integration, end-to-end, and performance testing.
• Experience building and operating production services with monitoring, distributed tracing, and incident troubleshooting.
• Strong communication skills to collaborate effectively across multidisciplinary teams.
• Ability to explain technical decisions clearly to engineering and business stakeholders.
• A track record of mentoring engineers and improving engineering practices through hands-on collaboration.
• Hands-on experience leveraging AI coding assistants and development tools (e.g., GitHub Copilot, Cursor, Claude) to accelerate software development, refactoring, and code generation.

Preferred

• Master's degree in Computer Science or Software Engineering.
• 8+ years of software engineering experience.
• Experience with API Gateways, service mesh technologies, and cloud networking concepts.
• Familiarity with OpenTelemetry, Grafana, Prometheus, or similar observability platforms.

Pay

• Exposure to web and mobile application development 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.
• For more information, check out the "About Us" section.
• $121,500.00 - $145,500.00

Benefits

• 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.