1) Recommendation using Business layer in .Net portal:
a. Application portal should have business layer to provide business logic, calculation functions or custom logic accessible through custom Web API and can be used in application portal as well as other integrated systems.
b. Business layer reduces the code duplication and efforts to develop for multiple system.
c. Application is easily extendible with existing and future enhancement.
2) Recommendation for Data Access layer for .Net Portal:
a. Business layer or Web APIs can use data access layer functions commonly to access data from database.
b. SQL views or stored procedure customization would be in control with Data access layer in place.
c. Reduced duplication of SQL queries and restrict the stored procedures, views or direct updating at database level.
d. Entity framework will be used to implement CRUD operation.