Three-tier architecture, ASP NET, business layer, data access layer, presentation layer, Windows server, IIS, .NET framework, C# language, SQL Server database, Entity Framework ORM, LINQ query, ASPX page, HTML5, CSS3, JavaScript, jQuery, Ajax, JSON data format, RESTful API, modern web application, clean architecture, loosely coupled components, scalability, maintainability, security, cloud deployment, Azure platform, virtual machine, load balancing, auto-scaling, monitoring dashboard, performance metrics, Uptime Robot, PagerDuty integration.