Staff Software Development Engineer – Agentic Applications and Experiences

WEX Fleet Services is transforming fleet payments by building agentic, scalable solutions for its fuel card platform. The Staff Software Development Engineer will design, develop, and enhance cloud-native agentic applications and experiences using Java, AWS, Kafka, Elasticsearch, containerization, and API-driven architectures while contributing to system architecture and operational excellence.

Responsibilities:

• Design, develop, and deliver delightful product experiences that are powered by Agentic capabilities, scalable, reliable software solutions using modern technologies such as Java, Kafka, Elasticsearch, and cloud-native platforms
• Contribute to architecture and design decisions that support highly available, secure, and scalable systems
• Build and maintain clean, efficient, well-tested, and maintainable code
• Develop and optimize RESTful APIs and backend services
• Participate in code reviews, technical discussions, and collaborative problem-solving sessions
• Troubleshoot, debug, and resolve complex technical challenges
• Work across technology stacks and quickly adapt to new tools and frameworks
• Stay current with emerging technologies and industry best practices to continuously improve engineering practices
• Ensure operational excellence and best customer experience for all the products and systems owned by the team

Requirements:

• Bachelor's degree in Computer Science, Engineering, or a related technical field
• 7+ years of software engineering experience designing, developing, and supporting enterprise-scale applications
• Strong experience building cloud-based applications and infrastructure using infrastructure-as-code practices
• Proficiency with event streaming platforms such as Kafka
• Experience with Elasticsearch, including indexing strategies, query optimization, and data analysis
• Experience working with cloud platforms such as AWS
• Strong understanding of software engineering principles, including data structures, algorithms, object-oriented design, scalability, availability, and reliability
• Strong problem-solving skills with the ability to analyze complex technical challenges
• Excellent written and verbal communication skills with a collaborative mindset
• Master's degree in Computer Science, Software Engineering, or a related field
• 8+ years of software engineering experience
• Experience and knowledge in building Agentic/AI solutions for real world problems
• Experience designing and implementing event-driven architectures
• Experience working with card payments or financial services platforms
• Hands-on experience with cloud-native technologies including Docker and Kubernetes
• Knowledge of API security principles and PCI DSS compliance requirements
• Experience working within existing codebases and improving legacy systems
• Strong backend development expertise with Java or C#, including frameworks such as Spring Boot
• Experience designing, building, and optimizing RESTful APIs, OData services, and SQL-based solutions
• Proven experience developing internet-scale services with a focus on scalability, security, availability, and reliability