Staff Software Engineer, Backend & APIs

WEXWEXUS•Seattle, WA

44d•$140,600 - $173,100

About The Position

WEX is seeking a Staff Software Engineer with deep backend development expertise to join its 10-4 by WEX team. The role designs, develops, and operates scalable, secure, and resilient backend services and APIs supporting mobile and web applications. The engineer works closely with mobile, web, product, platform engineering, security, infrastructure, and DevOps teams to deliver distributed systems and seamless customer experiences. The platform helps owner-operators and small fleets save on fuel through a large fuel discount network. Its mobile application lets drivers find participating fuel locations, activate discounts, manage payment methods, review transaction history, and access real-time fuel pricing and savings. The Staff Software Engineer builds the backend services that support these experiences and helps ensure they are secure, scalable, highly available, and reliable for drivers on the road. This role also provides technical leadership across engineering teams through architecture and system design, mentoring, technical documentation, operational improvements, and cross-functional initiatives. It includes hands-on use of 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 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, 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 Redis or other caching technologies 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 using AI coding assistants and development tools such as GitHub Copilot, Cursor, or Claude to accelerate software development, refactoring, and code generation.

Nice To Haves

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 Android and/or iOS application development, including mobile architecture, API consumption patterns, offline synchronization, and application performance considerations.
Experience leading technical initiatives across multiple engineering teams and mentoring senior engineers.

Responsibilities

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

Benefits

Health insurance
Dental insurance
Vision insurance
Retirement savings plan
Paid time off
Health savings account
Flexible spending accounts
Life insurance
Disability insurance
Tuition reimbursement
Quarterly or annual bonus eligibility for non-sales roles, according to role and applicable plan