Who fills out routing tables?

Routing tables are filled by the operating system and network protocols. In the context of programming in Go, when it comes to routing HTTP requests, the developer or framework fills the routing tables by linking URL paths with handlers. For example, in Go, using the net/http package or frameworks like Gin or Echo, routes are explicitly defined in the code:

http.HandleFunc("/users", usersHandler)
http.HandleFunc("/products", productsHandler)

Thus, the developer is responsible for filling the routing tables at the application level.