Senior Software Engineer (C#/.NET & AI)

Please note: This role is open only to candidates located in Chicago, IL; Dallas, TX; New York City, NY; Boston, MA; or Portland, ME.

We are currently unable to provide immigration sponsorship or support, either now or in the future.

At WEX, we simplify the business of running a business. Our WEX Benefits solutions reduce complexity and help employers manage the cost and administration of employee benefits.

We are looking for passionate technologists, collaborators, and problem solvers to join our Benefits Technology team as we build the next generation of employer benefits platforms and services.

As a Senior Software Engineer, you will work closely with Product Managers, customers, and engineering peers to understand the challenges employers face in the evolving benefits landscape. You will design and deliver scalable, high-quality solutions using modern engineering practices, including test-driven development and cloud-native architectures.

You will have the opportunity to contribute to mission-critical systems, influence technical direction, and help shape engineering standards across the team.

How You’ll Make an Impact

• Partner with Product and stakeholders to understand customer challenges and translate them into technical solutions
• Design, build, test, and deploy scalable, secure, and high-quality software solutions
• Use data to measure outcomes, validate assumptions, and drive engineering decisions
• Develop and maintain microservices and event-driven architectures
• Strengthen engineering practices including TDD, BDD, and CI/CD automation
• Support production systems through monitoring, incident response, and continuous improvement
• Identify performance bottlenecks and optimize systems for scalability and reliability
• Mentor peers and contribute to a culture of technical excellence and continuous learning
• Take ownership of work, operate independently, and deliver high-quality outcomes with minimal supervision

Experience You’ll BringSoftware Engineering & Systems

• 7+ years of software engineering experience
• Strong background in backend development, distributed systems, and scalable architecture
• Proficiency in modern backend technologies such as C#, .NET, Java, or Python
• Strong understanding of data structures, algorithms, and object-oriented design
• Experience building and consuming REST APIs
• Hands-on experience with React or modern UI frameworks
• Experience with relational and NoSQL databases (e.g., SQL Server, PostgreSQL, MySQL, MongoDB)
• Strong knowledge of CI/CD pipelines and Git-based workflows
• Experience with cloud-native development in AWS or Azure
• Understanding of software security principles and OWASP guidelines
• Experience writing unit tests and maintaining high test coverage
• Familiarity with Agile development methodologies
• Proven ability to deliver complex projects on time

Cloud, DevOps & Infrastructure

• Experience with cloud services (AWS or Azure), including IAM, compute, storage, and API services
• Familiarity with containerization using Docker and orchestration using Kubernetes
• Exposure to CI/CD tools such as GitHub Actions, GitLab CI, or Jenkins
• Basic understanding of Infrastructure-as-Code (Terraform preferred)
• Familiarity with observability tools (Prometheus, Grafana, CloudWatch, Azure Monitor)

AI, Agentic Systems & Emerging Technologies

• Familiarity with LLM concepts and frameworks such as LangChain, LlamaIndex, LangGraph, or CrewAI
• Exposure to Retrieval-Augmented Generation (RAG) and interest in evolving toward Agentic RAG systems
• Understanding of agentic workflows including tool use (function calling) and state management
• Awareness of vector databases (e.g., Pinecone, Milvus) and semantic search concepts
• Interest in emerging protocols such as Model Context Protocol (MCP)
• Experience or curiosity in building AI-native features and LLM-based automation in CI/CD pipelines

Leadership & Collaboration

• Bachelor’s degree in Computer Science, Software Engineering, or related field
• Strong collaboration skills in agile, cross-functional, and distributed teams
• Ability to communicate technical concepts and trade-offs clearly to both technical and non-technical stakeholders
• Proven ability to work effectively in geographically distributed teams
• Self-driven, proactive, and highly accountable for deliverables
• Continuous learner with strong interest in evolving cloud and AI technologies

Technology Must-Haves

• C# / .NET (or equivalent backend language such as Java or Python)
• React
• REST API development (ASP.NET or equivalent frameworks)
• Docker
• Kubernetes
• SQL & NoSQL databases
• Cloud platforms (AWS / Azure)
• CI/CD pipelines
• Event-driven architecture

Nice to Have / Learn Quickly

• Terraform
• Helm / ArgoCD
• GitHub Actions
• GraphQL
• Kafka
• Azure advanced services

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