ASP.NET Core 8 Web API, ASP.NET Core MVC (Razor), .NET 8 Worker Service, EF Core 8, SQL Server, SignalR, Hangfire, Azure AD (Microsoft.Identity.Web), EPPlus, Serilog. Built full-stack attendance tracking system: 5-project clean architecture (Core, Infrastructure, API, Web, Windows Agent). Implemented Azure AD OAuth2/OIDC auth (PKCE for API, cookie-based for MVC), JWT validation, role-based policies (Admin/Manager/Employee), custom claims transformation from DB roles. Designed EF Core schema: attendance sessions, behaviour events, audit logs, offline agent queue. Built REST API: attendance check-in/out, reports, behaviour events, AD sync, health checks (Swagger docs). Developed real-time dashboard with SignalR for live attendance status. Built Hangfire background jobs for AD sync (every 15 min). Created .NET 8 Windows Service agent reading Security Event Log (logon/lock/idle events), offline queue auto -flush to API.