What should be the ideal layout or architecture of any web/e-commerce application?

Hi Geeks, While working as the web developer I have seen different types of layouts for the web application but wanted to know that what should be the best or appropriate layout for any web application or e-commerce application like what should be the folder structure, how front-end views should be, how models, controllers should be (in case of MVC), how third-party APIs should be handled, hosting etc.