Senior Software Engineer - .NET; Full Stack

Job Description

This position is not eligible for visa sponsorship, now or in the future. Candidates must be a US Citizen or valid Green Card Holder.
This position is hybrid in the following office locations:
Cincinnati, OH (3 days) or Denver, CO (2 days).
Ready to take your career global? Make your mark at one of the biggest names in payments. We’re looking for a Senior Software Engineer - .NET (Full Stack) to join our ever-evolving Launchpad team and help shape the future of global commerce.

• Design, develop, and maintain full-stack web applications using C#, ASP.NET Core, .NET, SQL Server, and modern JavaScript frameworks, while leading application modernization initiatives, including the migration of large-scale legacy .NET Framework 4.x applications to .NET Core/.NET, driving cloud-ready architectures, improved performance, scalability, and long-term maintainability.
• Design and implement responsive, user-friendly frontend applications using JavaScript, Type Script, HTML5, CSS3, and modern frameworks such as Vue.js, React, or Angular, while collaborating closely with UX/UI designers, product owners, architects, and cross-functional development teams to deliver high-quality end-to-end solutions
• Develop and maintain RESTful APIs, backend services, and integrations with internal and external systems.
• Create reusable UI components, libraries, and shared services to improve development efficiency and consistency.
• Develop and execute unit, integration, and automated tests to ensure application quality and reliability.
• Participate in code reviews, technical design sessions, architecture discussions, and sprint planning activities.
• Troubleshoot and resolve application defects, production issues, and performance bottlenecks.

• Bachelor's degree in computer science, Engineering, Information Systems, or equivalent practical experience, with 8+ years of software development experience in enterprise application environments.
• 6+ years of hands‑on C# development experience with deep expertise in .NET Framework, ASP.NET MVC, ASP.NET Web API, ASP.NET Core, and modern .NET platforms (.NET Core/.NET 8+).
• Proven experience leading application modernization initiatives, including large-scale migrations from .NET Framework 4.x to .NET Core/.NET, enabling cloud‑ready, scalable, and maintainable solutions.
• Strong frontend development experience using JavaScript, Type Script, HTML5, CSS3, and modern frameworks such as Vue.js, React, or Angular, including building and consuming RESTful APIs.
• Extensive knowledge of Entity Framework, LINQ, SQL Server, relational database design, authentication, authorization, and web security best practices.
• Proficiency with Git, CI/CD pipelines, Dev Ops practices, automated testing (unit and integration), and code quality/security tools including Snyk, Checkmarx, and Black Duck.
• Strong technical leadership, analytical problem‑solving, and communication skills, with experience mentoring engineers and delivering solutions in Agile development environments.

• Acts like an owner by taking initiative, driving outcomes independently, and proactively engaging stakeholders to ensure successful delivery.
• Demonstrates curiosity and continuous learning, quickly acquiring new technical and business knowledge to make informed decisions and add value.
• Collaborates effectively across teams, seeking clarity when needed, sharing knowledge openly, and helping the broader team succeed.

Our inclusive and global teams win together every day. We’re proud to have the best minds in the industry, who you can learn from as you grow your career. The people, the energy, the connections – it’s unmatched. Come and be part of an ever‑evolving company and get…