If I submit details on one UI it will get write in one DB after that using Integration it will automatically write in the another DB with same details. How can I achieve this?

It is a sequence of steps right? 

From UI to DB then DB to another DB using API calls. 

If so, you have to configure the process model in such a way as to achieve this flow. 

yes through process model

As a certified senior developer, that should not be a challenge.

Do you have any specific question?