Staff Software Engineer, Backend & APIs

WEX Inc is seeking a Staff Software Engineer with deep expertise in backend development to join their 10-4 by WEX team. The role involves designing, developing, and operating scalable backend services and APIs that enhance customer experiences for mobile and web applications.

Responsibilities:

• Design, develop, and maintain scalable, secure, and high-performance backend services using Java, Spring Boot, PostgreSQL, and REST APIs
• Architect and build distributed microservices that are resilient, observable, and easy to maintain
• Design REST APIs that enable seamless integration with mobile applications, web applications, and external partner systems
• Lead architecture and system design discussions, producing high-quality design documents and driving alignment across engineering teams
• Optimize database design, queries, indexing strategies, and transaction management to improve performance and scalability
• Develop comprehensive automated testing strategies, including unit, integration, contract, performance, and load testing
• Improve application reliability by implementing observability, logging, distributed tracing, health monitoring, and alerting
• Identify technical debt, scalability bottlenecks, and reliability risks, and drive continuous platform improvements
• Build and enhance CI/CD pipelines, deployment automation, infrastructure automation, and engineering productivity tools
• Partner closely with Product, Mobile, Web, Security, Infrastructure, and DevOps teams to deliver high-quality customer experiences
• Lead code reviews, mentor engineers, establish engineering best practices, and raise the overall quality bar across the organization
• Troubleshoot complex production issues, perform root cause analysis, implement corrective actions, and improve operational excellence
• Evaluate emerging technologies and architectural approaches, providing technical recommendations based on business and engineering needs
• Create and maintain technical documentation including architecture documents, API specifications, runbooks, operational guides, and readiness plans
• Design highly available services with appropriate resilience patterns including retries, circuit breakers, caching, rate limiting, and graceful degradation
• Drive cross-functional initiatives as a technical lead or Single-Threaded Owner (STO), helping unblock teams and ensuring successful delivery
• Gain hands-on experience with automation and AI-assisted software engineering solutions

Requirements:

• Bachelor's degree in Computer Science, Software Engineering, or a related field
• 8–10 years of professional software engineering experience
• Strong expertise in Java and Spring Boot for building enterprise-grade backend applications
• Experience designing and developing RESTful APIs and distributed microservices
• Strong understanding of object-oriented design, data structures, algorithms, and software design principles
• Experience with PostgreSQL or other relational databases, including schema design, query optimization, indexing, and transaction management
• Experience building scalable, secure, highly available, and fault-tolerant distributed systems
• Strong understanding of authentication, authorization, API security, OAuth2, JWT, and secure software development practices
• Experience with asynchronous messaging technologies such as Kafka, RabbitMQ, or similar event-driven platforms
• Familiarity with caching technologies such as Redis and distributed caching strategies
• Experience with CI/CD pipelines, automated testing, code quality tools, and modern software delivery practices
• Understanding of observability technologies including logging, metrics, tracing, monitoring, and alerting
• Experience collaborating with mobile engineering teams and designing APIs optimized for iOS and Android applications
• Excellent communication, collaboration, mentoring, and technical leadership skills
• Hands-on experience leveraging AI coding assistants and development tools (e.g., GitHub Copilot, Cursor, Claude) to accelerate software development, refactoring, and code generation
• Master's degree in Computer Science or Software Engineering
• 10+ years of software engineering experience
• Experience with cloud-native application development using AWS, Kubernetes, Docker, and Terraform
• Experience with API Gateways, service mesh technologies, and cloud networking concepts
• Experience with event-driven architectures and distributed systems patterns
• Familiarity with OpenTelemetry, Grafana, Prometheus, or similar observability platforms
• Exposure to mobile application development (Android and/or iOS) with an understanding of mobile architecture, API consumption patterns, offline synchronization, and application performance considerations
• Experience leading technical initiatives across multiple engineering teams and mentoring senior engineers