throw someone in at the deep end
idiomPart ofdeep
throw someone in at the deep end — idiom
1. to make someone start doing something new and difficult without giving them any
1.idiom
Definition
to make someone start doing something new and difficult without giving them any help or preparation
Example
The new teacher was thrown in at the deep end and had to manage a class of forty students on her first day.
Instead of training us first, the manager threw us in at the deep end with the biggest client account.