Editor
noun
An edit is 編集. Someone who does those edits is an editor!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own. Also, the readings from 編集 should help you.
その本の編集者として任命されてから、過労気味です。
Since being designated as editor of the book, I’ve been feeling overworked.