Wex

Senior Backend Software Engineer

United States March 2, 2026 Workday

About the Team/Role:

We are seeking a seasoned Senior Backend Software Engineer in the WEX Mobility Engineering organization. This role will sit in the Mobility team that caters fleet management and mobility payments solutions to our large customers. Mobility development team spans across USA, Brazil, and India. Our Mobility systems provide SaaS and API solutions to various customers. WEX Mobility products enable credit issuance to fleet companies and their workers in the form of WEX or cobranded credit cards, usable at fueling stations and select other merchants. At WEX, we provide fleet managers and operators with fuel discounts, and flexibility to configure spend controls that restrict fleet members to use their cards at configured merchants, for configured amounts and velocity.

​How you’ll make an 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.

​Experience you'll bring:

  • 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.

Preferred Qualifications:

  • Master’s degree in computer science or software engineering.

  • 8 years of experience in software engineering. 

  • 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

  • Ability to work on existing codebase, contribute improvements, and adapt to legacy systems’ constraints.

The base pay range represents the anticipated low and high end of the pay range for this position. Actual pay rates will vary and will be based on various factors, such as your qualifications, skills, competencies, and proficiency for the role. Base pay is one component of WEX's total compensation package. Most sales positions are eligible for commission under the terms of an applicable plan. Non-sales roles are typically eligible for a quarterly or annual bonus based on their role and applicable plan. WEX's comprehensive and market competitive benefits are designed to support your personal and professional well-being. Benefits include health, dental and vision insurances, retirement savings plan, paid time off, health savings account, flexible spending accounts, life insurance, disability insurance, tuition reimbursement, and more. For more information, check out the "About Us" section.

Pay Range: $121,500.00 - $145,500.00
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How to Get Hired at Wex

  • Research which of WEX's three business segments (Fleet, Corporate Payments, Health & Benefits) your target role serves, and tailor every application material to that segment's specific language, challenges, and competitive landscape
  • Optimize your resume for Workday by using a single-column layout, standard section headers, and explicit keyword matches from the job posting — then manually verify every auto-parsed field in your candidate profile before submitting
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