Journeys - How to set up a webhook that triggers when a contact meets the goal criteria?

Journeys - How to set up a webhook that triggers when a contact meets the goal criteria?

Hi there, I'm setting up a journey on Marketing Automation. 
The main goal of the journey is to get the leads to reply our emails. 
Is there a way to trigger a webhook when that goal is met? The webhook would then trigger a notification. Is that possible?
So far, I have created many "if" branches at every step of the journey, but that does not seem to be the most optimal way of doing it.