Come in and discuss ajax, Layer 3, and mvc

Come in and discuss ajax. I wrote a small project on Layer 3 and mvc. I used three layers (interface layer, business logic layer, and data layer ). Later, a large number of ajax applications were added. If we find that Layer 3 and ajax are used in projects together, there are great disadvantages. Ajax is like a server that submits a request and processes the returned results. For the traditional layer-3 architecture, ajax cannot submit requests to the business logic layer. Let's discuss ajax, Layer 3, and mvc.
I wrote a small project by myself and used to use three layers (interface layer, business logic layer, and data layer ).

Later, a large number of ajax applications were added.
If we find that Layer 3 and ajax are used in projects together, there are great disadvantages.
Ajax is like a server that submits a request and processes the returned results. For the traditional three-tier architecture,
Ajax cannot commit a request to the business logic layer. The business logic layer generally involves some processing functions.

Therefore, I made the following summary:
If ajax is used in many projects, design the project as mvc.
In this way, ajax requests can be processed well using the controller in mvc.

I don't know if this summary is correct. please click it!
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Whether it's "three layers", "MVC", or other..., as long as you return additional data to AJAX, it will be terrible.
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The three layers you mentioned are like MVC, and the controller is the logic processing layer. if you do a good job of division of labor, you will not say that.