He joined the House of Givenchy in 1983 as a design assistant and was named studio director and premier assistant to Hubert de Givenchy for Pret-a-porter and haute couture in 1989, a post he held until his departure from the House in 1997, also working with John Galliano and Alexander McQueen. While at Givenchy, Arend's additional responsibilities included the design and production of Givenchy accessories (jewelry, shoes, handbags, gloves, sunglasses, furs and swimwear).