Is it usual for startups in Berlin to terminate the contract before it begins?

A startup in Berlin said they wanted to hire me for a backend position.

The contract was signed by both parties, I got a work permit visa, I quit my job and I was going to start in two weeks time.

They phoned me and said they've changed their plans and they are no longer going to hire for a backend position.

Needless to say I was very disappointed, my life got upside down because of that... I've posted in Reddit and three people reached me saying that Berlin is just like that, that this happened to them as well. (One in an unicorn evaluated pretty highly)

Now I am wondering if I should seek other positions in Berlin or not. Anyone has experience to share?

Thanks