Senior Backend Engineer – AI Platform

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 seasoned Sr. Software Engineer in the North America Mobility organization. This role will sit in the Platform team that focuses on building AI Platform to support the feature development team to build robust features faster.  You will contribute to the architecting and realization of our next-generation Agentic AI Platform. Within this capacity, you will be responsible for the design, development, and deployment of autonomous AI agents, skills, MCP servers, AI tools engineered for advanced reasoning, strategic planning, and the orchestration of intricate financial and operational workflows. Operating at the vanguard of generative AI, distributed systems, and fintech, you will empower WEX to deliver highly intelligent, proactive solutions to an expansive global user base.  Our Platform team is dedicated to architecting scalable, robust, and maintainable UI and API platform solutions that empower internal feature development teams to build at velocity. Within the NAM Mobility ecosystem, our products facilitate strategic credit issuance to fleet organizations and their workforce through WEX-branded or co-branded credit instruments, accepted across a vast network of fueling stations and merchant partners. We provide fleet managers and operators with advanced spend orchestration capabilities, encompassing fuel discounts and sophisticated spend controls that permit precise configuration of merchant restrictions, transaction limits, and velocity thresholds to optimize operational efficiency. How you’ll make an impact: Design, develop, and maintain robust, scalable, and high-performance object oriented code in our backend services. Develop public REST APIs using Java and internal gRPC APIs for inter-service and inter-system communication. Craft systems designs, lead design decisions, and drive alignment with other senior engineers. Write automated unit tests, integration tests, end-to-end tests, concurrency tests, load/performance tests. Analyze existing systems to identify bottlenecks, tech debt, and implement scalability, and stability improvements. Implement automation for testing, monitoring, healing, and scaling applications, continuous integration and deployment to reduce time to market. Collaborate with cross-functional teams, including product managers, designers, and other engineers, to define and implement new features. Conduct code reviews (comment, approve, seek revisions, merge), mentor junior and mid-level engineers, and actively promote engineering best practices. Dive deep and troubleshoot complex issues, devise fixes, author root cause analysis documents, and ensure lasting performance and reliability. Conduct objective and comparative analyses of competing…