While it's true that a product's innovation should not extend to the grammar or spelling of its homepage copy, "all your developer needs" is correct. "developer

While it's true that a product's innovation should not extend to the grammar or spelling of its homepage copy, "all your developer needs" is correct. "developer" is an attributive noun: https://www.thoughtco.com/what-is-attributive-noun-1689012 https://www.thoughtco.com/what-is-attributive-noun-1689012