I used to work for a company where they change the offer after the staff come to work on first day.
They just "offer" but sign contract on first day.

Don't accept this kind of arrangement, I've seen that company change their offer few times.
Basically they put a very nice job title etc to lure people to join.

But when joined its for a lesser role. Etc. In the end like 5 people quick after first day. Also feel sad for them cause they probably quit their previous role thinking its a "manager" role here but it's really just a lie.

Example QA manager in job title but actually is just qa lead. And also not really lead cause only he one person.

Such is working life.