Senior Software Engineer - .NET (Full Stack)

Worldpay•Denver, CO

1d•Hybrid

About The Position

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. Launchpad is a Worldpay application designed to streamline merchant onboarding. It collects all necessary merchant details, enabling businesses to quickly start accepting credit card payments and settle transactions on the Worldpay platform. Launchpad includes both a user-friendly UI and robust API components to support seamless integration.

Requirements

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, TypeScript, 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, DevOps practices, automated testing (unit and integration), and code quality/security tools including Snyk, Checkmarx, and BlackDuck.
Strong technical leadership, analytical problem-solving, and communication skills, with experience mentoring engineers and delivering solutions in Agile development environments.

Nice To Haves

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.

Responsibilities

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, TypeScript, 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.