Senior C# Developer

Code & Pepper supports clients in demanding industries by helping them scale teams and build advanced digital products. We are supporting a project that involves the development and modernization of a FinTech payment platform based entirely on C# (.NET) technology. The scope of work includes the implementation of tokenization for Apple Pay, the redesign of onboarding processes, and direct integrations with correspondent banks and transaction service providers. In this role, you will be responsible for developing key payment modules, integrating with external institutions, and ongoing system maintenance and optimization. Requirements: Commercial experience in backend design and programming in C# (.NET / .NET Core). Practical experience in payment gateway integration, transaction processes, or tokenization (e.g., Apple Pay). Proficiency in creating, optimizing, and integrating REST APIs and webhook mechanisms. Experience integrating with external APIs of financial institutions or banks. Practical knowledge of relational databases (e.g., MS SQL, PostgreSQL) and SQL query optimization. Experience in refactoring, modernizing backend processes (e.g., user onboarding), and maintaining production systems. Ability to write unit and integration tests (e.g., xUnit, NUnit). Knowledge of software architecture principles (Clean Architecture, SOLID, design patterns). Experience working with the Git version control system and workflows.