Events of adding and changing a record to a custom object

My task is to configure processes for the add event and change the record in the table. For this event, you must start the process or give a signal to an existing process.
I was thinking about a trigger in the database, but this is too low-level and I want a more beautiful solution. Searching with a filter for the value of variables in running instances will not solve the problem, because the value in the custom object in the table can be changed by the external system, I need the actual value. I also need to understand how the external system will write the value to it so that it also gives an event.
Has anyone encountered this problem and which way to go?

Hi Evgeny,

what do you mean by “the table” and “the external system”? Can you elaborate a little more on what problem you’re trying to solve?


after completion of the user task. I plan to save the data in the database.
How to initiate a signal of this action to start processes?