In At The Deep End Meaning

(idiomatic)

Example:   To be put into a complex situation (especially work-related) without preparation or when lacking experience in the field; especially in the case of a new job. Derived from the slope in a swimming pool which is shallow at one side, for beginners, and has a deeper section which is designed for more experienced swimmers.
  Also 'jump in at the deep end' - to deliberately tackle a difficult area; to take the bull by the horns