Senior Software Engineer – C# / .NET

About Threecolts Threecolts is a software suite built for consumer brands, helping them recover revenue, operate more efficiently and grow across major retailers and marketplaces. Our largest business, Margin Pro, helps brands recover money owed to them by retailers and marketplaces such as Amazon, Walmart and Target by managing disputes on their behalf.

Alongside this, we’re building and scaling newer products, including AI Operator and Retail 365, while continuing to grow our portfolio of subscription products across our customer base. Who We Are We’re a global team of 340 people across 33 teams, having grown through 24 acquisitions. We operate with a flat structure, giving people real ownership and the ability to move quickly.

AI is embedded in how we work across the business, helping us increase speed, improve quality and operate at scale. Key Responsibilities You’ll take ownership of features across Inventory Lab’s C# and .NET-based systems, delivering them from initial design through to production. You’ll design, develop, and maintain clean, scalable backend services, APIs, and application components using C# and the .NET ecosystem. You’ll work with modern .NET technologies, including ASP.NET and ASP.NET Core, to build and maintain reliable, high-performance web applications and services. You’ll focus on writing maintainable, well-tested code that supports the product’s evolving requirements. You’ll develop and maintain front-end features using Vue.