Senior Backend Software Engineer

WEX

Senior Backend Software Engineer developing scalable backend solutions and REST APIs for fleet management systems at WEX. Collaborating with cross-functional teams and leading design decisions.

Posted 5/20/2026full-timeRemote • California • 🇺🇸 United StatesSenior💰 $121,500 - $145,500 per yearWebsite

Tech Stack

Tools & technologies

CloudDockerGRPCJavaKafkaKubernetesSpring BootSpringBootSQL

About the role

Key responsibilities & impact

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

What you’ll need

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
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

Benefits

Comp & perks

health, dental and vision insurances
retirement savings plan
paid time off
health savings account
flexible spending accounts
life insurance
disability insurance
tuition reimbursement

ATS Keywords

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Hard Skills & Tools

JavaC#SpringBootREST APIsgRPCSQLdata structuresalgorithmsobject-oriented designevent-driven architecture

Soft Skills

problem-solvingcommunicationcollaborationmentoringleadershipanalytical thinkingempathydocumentationtroubleshootingcontinuous improvement