Stephanie Simpson is the head writer for Octonauts. She has also been the Executive Producer for Octonauts as well. She also produced and wrote other series and movies, such as Arthur, Hilda, Barney and Friends, The Wubbulous World of Dr. Seuss, Wishbone, and many more.
She was credited as an Executive Producer and Head Writer from Season 1 to Above & Beyond Season 1, as well as the Netflix specials (only head writer for The Octonauts and the Ring of Fire special, though). Her absence after over a decade of working on the franchise starts in Above & Beyond Season 2.