Fullstack Software Engineer Intern (Undergraduate)

WEX, Inc.; United States; Hybrid; USD 37,000 - 48,000; Full time

Benefits offered by this job

Mentorship

Professional development

Weekly learning experiences

Remote, hybrid and onsite options

Job summary

WEX, Inc. is offering a 13‑week paid Software Engineer Internship across the United States. You will work with engineers and product managers to build scalable applications and AI‑driven features in a modern cloud stack.

Current students pursuing a BS in CS or related field will gain hands‑on experience with React, C#/.NET, and SQL/NoSQL databases, with mentorship and weekly learning sessions. Remote, hybrid, and onsite options are available.

Qualifications

• Pursuing a Bachelor's degree in Computer Science, Machine Learning, Software Engineering, or related field, with at least Sophomore year completed.
• Hands-on experience with React, C#/.NET, and SQL/NoSQL databases.
• Foundational understanding of high-level software architecture, microservices, RESTful design concepts.
• Familiarity with AI agent frameworks (e.g., LangChain, Semantic Kernel) and LLM concepts.

Responsibilities

• Ship Full-Stack Features: build UI with React and backend with C#/.NET including API development.
• Build AI Solutions: prototype and deploy AI agents or LLM integrations to automate workflows.
• Understand System Design: learn architecture principles and how microservices, APIs, and data flows connect.
• Learn & Collaborate: apply TDD/BDD and receive mentorship from senior engineers.

Skills

React

C# / .NET

RESTful design

Problem solving

Education

Bachelor's degree in Computer Science or related

Tools

SQL/NoSQL databases

LangChain

Semantic Kernel

Job description

WEX is a global commerce platform that has been simplifying the way businesses operate for over 40 years. Our purpose is simple: to reduce administrative burdens, streamline payments, and manage mobility. With a team of over 7,200 professionals across 16 countries.

Our specialties are employee benefits, business payments, and fleet/mobility solutions. We support more than 20 million SaaS accounts, 8 million Health Savings Accounts, and 19+ million vehicles worldwide. We're a growing company with a history of innovation and a focus on our customers, making this a great place to grow your career.

The WEX Summer Internship Program: Learn, Lead, and Make an Impact

Our 13-week paid internship program, running from late May to mid-August, is a chance for you to gain real‑world experience and develop your skills. Recruiting begins in September and continues through December at our various locations across the U.S.

You won't just be a bystander; you'll work on impactful projects and contribute to WEX's mission. We provide mentorship, professional development, and weekly learning experiences to help you build confidence and leadership skills. High‑performing interns may even get the chance to lead their own initiatives.

We offer remote, hybrid, and onsite options for flexibility, and our goal is to bring top interns back full‑time or offer them extended roles during the school year. Imagine starting your career with a company that’s building what's next. Your future starts here.

About the Role:

As a Software Engineer Intern, you will work alongside engineers and Product Managers to solve real‑world business challenges. You will gain hands‑on experience building scalable applications, learning modern engineering practices, and developing AI‑driven features within modern cloud architecture.

How you'll make an impact:

• Ship Full-Stack Features: Build user interfaces with React and backend services using C# / .NET, including basic database interactions and API development.

• Build AI Solutions: Prototype and deploy AI agents or LLM integrations to automate workflows and enhance product capabilities.

• Understand System Design: Gain hands‑on exposure to high‑level architecture principles, learning how microservices, APIs, and data flows connect across cloud systems.

• Learn & Collaborate: Apply TDD/BDD practices, work through the full software lifecycle, and receive mentorship from senior engineers on high-availability systems.

Experience you'll bring:

• Educational Foundation: Currently pursuing a Bachelor's degree in Computer Science, Machine Learning, Software Engineering, or a related field, having completed at least your Sophomore year prior to the start of the internship.

• Hands‑on academic or project experience with React, C# / .NET, and SQL/NoSQL databases.

• Foundational understanding of high-level software architecture, microservices, or RESTful system design concepts.

• Familiarity or interest in AI agent frameworks (e.g., LangChain, Semantic Kernel) and LLM concepts.

• Strong problem‑solving skills, adaptability, and eagerness to learn during a fast‑paced internship.

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: $27.00 - $35.00