What is the best way to employ a waiter in a coffee shop?

Due to the peculiarity of the work of a waiter, it cannot be subordinated to a civil law contract (subcontract, contract for the provision of services) - you formulated it as "through the FOP". After all, the waiter works according to the schedule, he must always be there, he does the work not once, but on a permanent basis, you will pay him for the process itself, and not for the result.

In addition, during the inspection, controllers of State Labor and Employment bodies may find violations for admitting an employee to work without concluding an employment contract and issue a resolution on the imposition of a fine. The court will consider the provided evidence and establish that the civil law contract concluded with an individual has signs of a labor nature.

According to Article 265 of the Labor Code (https://zakon.rada.gov.ua/laws/show/322-08#Text), the actual admission of an employee to work without an employment contract is a violation of labor laws, as a result of which a fine is imposed .

Therefore, it is better for you to officially employ the waiter, i.e. conclude an employment contract with him in accordance with Chapter 3 of KzpP.

In addition, please note that you are obliged to inform the Tax Service about hiring an employee.