Backend Engineer (Java, C#)

About The Role

We are seeking a seasoned Staff Software Engineer to join our North America Mobility organization remotely. This role is integral to our Platform team, which is focused on building a robust AI Platform to accelerate feature development and support complex financial workflows. As a key contributor, you will be responsible for designing, developing, and deploying autonomous AI agents, skills, MCP servers, and AI tools engineered for advanced reasoning, strategic planning, and orchestration of intricate operational processes. Operating at the intersection of generative AI, distributed systems, and fintech, you will enable WEX to deliver highly intelligent, proactive solutions to a broad global user base.

Qualifications

• Bachelor's degree in Computer Science or Software Engineering
• 8-10 years of professional experience in software engineering
• Strong understanding of data structures, algorithms, and object-oriented design
• Expertise in designing and developing internet-scale, scalable, secure, and reliable services
• Proficiency in backend development with Java or C#, including frameworks like SpringBoot
• Experience in building and optimizing RESTful APIs and working with SQL databases
• Hands-on experience with AI/LLM-powered applications and agent-based systems
• Familiarity with agent frameworks, orchestration patterns, and MCP or similar protocols
• Knowledge of prompt engineering, embeddings, and vector-based retrieval systems
• Excellent communication skills with a collaborative mindset

Responsibilities

• Design, develop, and maintain high-performance, scalable backend services using object-oriented programming
• Create and expose public REST APIs and internal gRPC APIs for seamless inter-service communication
• Lead system design discussions, make architectural decisions, and align with engineering standards
• Write comprehensive automated tests including unit, integration, end-to-end, and load/performance tests
• Analyze existing systems to identify bottlenecks, technical debt, and implement improvements for scalability and stability
• Implement automation for testing, monitoring, healing, and scaling of applications, including CI/CD pipelines
• Collaborate with product managers, designers, and other engineers to define and develop new features
• Conduct code reviews, mentor junior engineers, and promote best engineering practices
• Investigate and troubleshoot complex system issues, perform root cause analysis, and ensure system reliability
• Maintain detailed documentation including design documents, run books, and change management records
• Provide live-site support to ensure high availability and rapid incident resolution
• Lead cross-team projects as a technical owner or lead, facilitating progress and removing obstacles
• Design and build agentic AI systems, including autonomous workflows, reasoning, and multi-step decision-making capabilities
• Develop and scale multi-agent architectures supporting complex use cases across payments and fleet ecosystems
• Integrate AI systems with enterprise data sources using MCP or similar frameworks for secure interaction
• Build and optimize LLM-powered services for production environments, ensuring performance and cost efficiency
• Implement evaluation frameworks, observability, safety, and compliance measures for AI systems
• Design solutions for context management, memory, and retrieval-augmented generation to improve AI agent effectiveness

Benefits

• Comprehensive health, dental, and vision insurance plans
• Retail savings plan with company match
• Paid time off and holidays
• Health Savings Account (HSA) and Flexible Spending Accounts (FSA)
• Life and disability insurance coverage
• Tuition reimbursement and professional development opportunities
• Work-from-home flexibility and remote work support
• Employee assistance programs and wellness initiatives

Equal Opportunity

We are an equal opportunity employer committed to fostering an inclusive environment. We celebrate diversity and are dedicated to creating a workplace where all employees are valued and have equal access to opportunities for growth and development. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, age, disability, or any other protected status under applicable law.