Senior .NET Developer (Marketplace & Trading Platform Experience)

Tryzens Limited is a fast growing IT solutions consultancy based in the City of London with offices in Bulgaria, India and Australia. Our areas of expertise include delivery of eCommerce solutions, multi-channel retail solutions and project management amongst others. We provide best of breed solutions and services to several blue chip clients primarily within retail, financial services and other industries. We have built our delivery focused reputation upon technical innovation, in-depth business knowledge, and creative vision, all of which supports our objective of helping clients to gain true value from eCommerce. We love what we do and our clients love our work.

Position Summary

Due to expanding our team in Sofia we are looking for a Senior .NET Developer with a strong background in building scalable, high-performance systems with custom features for e-commerce or marketplace platforms. The ideal candidate will have hands-on experience in developing complex transactional systems for the trading of high-value goods—preferably in the wine, alcohol, or collectibles domain—and a deep understanding of integration with external data providers.

Key Responsibilities

• Design, develop, and maintain high-performance backend services using .NET (C#/.NET Core)
• Implement custom modules and features for wine/alcohol trading, including auction systems, direct buy flows, and inventory management
• Integrate with external APIs and data providers such as Wine-Searcher and Liv-ex to surface real-time price fluctuations and historical data
• Develop and optimize transaction workflows to support secure and efficient trading
• Collaborate with product managers, UI/UX designers, and QA teams to deliver high-quality solutions
• Ensure scalability, maintainability, and performance of the platform through clean architecture and best practices
• Lead code reviews, mentor junior developers, and contribute to technical decision-making
• Write unit, integration, and API tests to ensure code quality

Requirements

• 5+ years of professional development experience with C# and the .NET platform (.NET Core or later)
• Proven experience with custom implementation in marketplace or trading platforms
• Strong understanding of RESTful APIs, asynchronous programming, and microservices architecture
• Hands-on experience with third-party API integrations, especially data aggregation from platforms like Wine-Searcher and Liv-ex
• Experience with real-time systems, price tracking, and inventory synchronization
• Familiarity with secure payment processing, order management, and auction logic
• Solid knowledge of relational databases (SQL Server, PostgreSQL) and ORMs (e.g., Entity Framework)
• Experience with version control (Git), CI/CD pipelines, and agile methodologies

Nice to Have

• Domain knowledge or personal interest in wine/alcohol trading or collectibles
• Experience with frontend technologies like Angular, React, or Vue.js
• Exposure to cloud platforms such as Azure or AWS
• Experience working with distributed systems and event-driven architecture

Benefits

• Competitive salary and performance-based bonuses
• Remote-friendly culture with flexible working hours
• Opportunity to work on an innovative platform transforming an age-old industry
• Collaborative, fast-paced team focused on quality and user experience
• Professional development support and learning opportunities