Staff Backend Engineer – APIs, Microservices & Scale

WEX, Inc.; Town of Texas (WI); On-site; USD 141,000 - 173,000; Full time

Benefits offered by this job

Health insurance

Dental and vision insurance

Retirement savings plan

Paid time off

Health savings account

Flexible spending accounts

Life insurance

Disability insurance

Tuition reimbursement

Job summary

WEX, Inc. is seeking a Staff Software Engineer to lead backend development for a scalable, secure platform powering our fuel-discount network and driver experiences.

You will design, build, and operate high-performance services and APIs, collaborating with product, mobile, web, and platform teams to deliver reliable experiences for owner-operators and fleets. You will mentor engineers, drive architectural decisions, and improve observability, testing, and deployment practices while exploring

Qualifications

• Bachelor's degree in Computer Science, Software Engineering, or 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 to accelerate software development, refactoring, and code generation.

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 STO, helping unblock teams and ensuring successful delivery.
• Gain hands-on experience with automation and AI-assisted software engineering solutions.

Skills

Java

Spring Boot

REST APIs

Distributed systems

PostgreSQL

OAuth2/JWT

Kafka/RabbitMQ

CI/CD

Observability

AI coding assistants

Education

Bachelor's degree in CS/SE

Master's degree in CS/SE

Tools

AWS

Kubernetes

Docker

Terraform

OpenTelemetry

Job description

WEX, Inc. is seeking a Staff Software Engineer to lead backend development for a scalable, secure platform powering our fuel-discount network and driver experiences.

You will design, build, and operate high-performance services and APIs, collaborating with product, mobile, web, and platform teams to deliver reliable experiences for owner-operators and fleets. You will mentor engineers, drive architectural decisions, and improve observability, testing, and deployment practices while exploring