Staff Software Engineer (AI & Backend)

WEX is a company that specializes in mobility payments solutions, and they are seeking a seasoned Staff Software Engineer to join their Mobility Engineering organization. In this role, you will design and develop scalable backend services and public REST APIs, while collaborating with cross-functional teams to implement new features and enhance existing systems.

Responsibilities:

• 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 technologies to advise the team of pros and cons of a technology solution
• Maintain robust documentation (design docs, run books, change management docs, and readiness plans)
• Provide live-site support for production applications by monitoring systems, ensuring rapid incident resolution, and driving continuous improvement
• Drive cross-team projects as a single-threaded-owner (STO) or tech lead, and actively unblock other engineers to make progress

Requirements:

• Bachelor's degree in Computer Science or Software Engineering
• 5-8 years of professional experience in software engineering
• Strong understanding of data structures and algorithms, object-oriented design, and problem-solving skills
• Expertise in designing and developing internet-scale services with scalability, availability, security, and reliability design tenets
• Excellent written and verbal communication skills, and a collaborative and empathetic mindset
• Proficiency in backend development, with proficiency expertise in Java or C#, and frameworks like SpringBoot, building and optimizing RESTful APIs, ODATA framework, and SQL
• Ability to leverage AI-enabled development tools such as Cursor AI, Kiro and GitHub Copilot to accelerate feature delivery, automate documentation, and enhance code quality
• Master's degree in computer science or software engineering
• 10 years of experience in software engineering
• Experience with event-driven architecture and tools like Kafka
• Experience working on card payments
• Familiarity with cloud-native architecture (containerization using tools such as Docker and Kubernetes)
• Awareness of API security and PCI DSS compliance requirements
• Familiarity with mobile development (iOS or Android)
• Experience building AI skills & deploying AI solutions to production environments
• Experience building production-grade AI agents or copilots
• Familiarity with multi-agent systems and distributed AI architectures
• Experience with vector databases (e.g., Pinecone, Weaviate, OpenSearch, Milvus)
• Knowledge of AI evaluation techniques, safety practices, and responsible AI principles