Shifting to a different tool/technical/domain

Hello folks, I am humbly expecting, if you have gone through an experience where you decided to switch to a different tool / domain / technology out of your interest.

How was your struggle while learning and applying for a job or internal posting?

How did you overcome the fact that your previous experience is not aligned to the current tool / domain?

How did you crack the interview when you didn't have the hands on experience on that tool? Only Thing you had was learning and a certification to get started in that tool / domain??