[Vuejs]-Whats the best way to refresh the interface after I add a item data to database?

I think both the solutions are valid it depends on what kind of write operation we are planning to do. Given that you do all the validations on the front-end which leaves lesser chance for errors on the backend. I do the following based on the use case.

1. Add/Update the item locally and then based on the response from the server I remove it again in case of an error. This is an optimistic technique used by a lot of websites and worls really well for CRUD kind of operations.
2. Let’s say that your new operating is going to creaate a new user in a 3rd party api. So doing an optimistic thing might not be the best. So what I do is make the request, show a toast/alert that the request is happening, and then use sockets or long polling to get the changes. When the request is finally done show the data. In the meanwhile you can insert a dummy item showing loading.