Job Description – C# / .NET Core Developer (Long-term Project) We are looking for an experienced C# developer working in a .NET Core environment to help us build and expand several internal platforms for our fast-growing e-commerce company Vivid Green. Our company operates multiple e-commerce brands and marketplaces (including Bol.com) and we are currently building a centralized internal system that connects product management, warehouse operations, advertising, and investor reporting into a single platform. This is not a small task-based project, but a larger system that will continue to evolve. Therefore we are looking for a developer who enjoys building scalable systems and long-term architecture. What you will work on You will help develop and improve several internal tools, including: Investor dashboard A platform where investors can track: ROI per investment batch Status of product batches Financial performance and reporting Central internal platform A system that acts as the single source of truth for all teams within Vivid Green, including: product data compliance management inventory data operational insights Warehouse Management System (WMS) Improving and expanding our internal WMS with integrations such as: marketplace integrations logistics systems inventory synchronization Advertising management system A comprehensive internal tool that connects with advertising platforms such as: Facebook Ads Google Ads Bol.com Ads This system will help automate and optimize advertising performance. What we have already built We already have several internal systems running, including: An automated advertising tool used to improve product rankings on Bol.com A product management and compliance platform You will help expand and connect these systems into a larger integrated platform. Required skills Strong experience with C# Experience working in a .NET Core environment Strong SQL knowledge Experience with LINQ queries Experience building scalable backend systems Nice to have Experience building internal business platforms or dashboards Experience with API integrations Experience working with e-commerce or marketplace data Experience with advertising platforms APIs What we are looking for We are looking for a developer who: Thinks in systems and architecture Writes clean, scalable code Can work independently and propose solutions Is comfortable working on long-term projects About Vivid Green Vivid Green is a fast-growing e-commerce company building multiple consumer product brands across European marketplaces. Technology and automation play a key role in how we scale our business, which is why we invest heavily in building internal tools and systems. If this sounds like a project you would enjoy working on, we would love to hear from you. Please include examples of similar systems, platforms, or backend projects you have worked on.