C# (Windows Application) Developer for UAE Riayati & Tatmeen Integration -- 2

Project Title: C# .NET Developer Required to Integrate UAE Riayati (MOHAP) & Tatmeen APIs into C# WinForms Desktop Software Project Description: We are looking for an experienced C# .NET Developer / Healthcare Integration Specialist to integrate Riayati (MOHAP HIE) and Tatmeen (GS1 Serialization Track & Trace) APIs into our existing C# Windows Desktop Application (WinForms with SQL Server database) Riayati Integration (MOHAP HIE): Implement OAuth 2.0 and mTLS (Mutual TLS) certificate-based authentication using HttpClient / RestSharp in C#. Build FHIR R4 JSON schemas to Fetch e-Prescriptions (MedicationRequest) using Emirates ID (EID). Build FHIR R4 JSON schemas to Post Dispensing Events (MedicationDispense). Store and handle OAuth tokens securely in C# and log API response errors to SQL Server Tatmeen Integration (Track & Trace Serialization): Build a GS1 2D DataMatrix Barcode Parser in C# to extract: GTIN (01), Expiration Date (17), Batch/Lot Number (10), and Serial Number (21) from POS scanner inputs. Integrate with Tatmeen B2B REST APIs to register serial verification and dispensing events. Sync Tatmeen verification data with local SQL Server inventory records Database & UI Implementation: Extend existing SQL Server tables to store Riayati Transaction IDs, Tatmeen Serial Numbers, mTLS configuration parameters, and execution logs.Add C# UI components (WinForms) for barcode scanning feedback, error prompts, and manual e-prescription lookups. Perform end-to-end sandbox testing against official MOHAP/Tatmeen test endpoints.