Probably the part of the system where more of the business logic lives will be more difficult and interesting to develop. In modern projects, this probably star

Probably the part of the system where more of the business logic lives will be more difficult and interesting to develop. In modern projects, this probably starts in the front-end. These days, it is possible to develop quite a bit of business logic in the front-end, and it’s arguably delivered faster. In a mature project with significant scale, interesting parts of the business logic have to be implemented in the back-end.