Source: https://www.dice.com/career-advice/game-developer-career-path-key-things-to-know
This approach is commonly used when intricate, extensive projects demand a range of skills that one company may not have. For instance, one co-developer might be tasked with engineering the
game engine while another concentrates on designing detailed
character models and environments.
On the other hand, outsourcing is employed by companies that need to assign specific tasks while maintaining oversight over the contractor's work. For example, a
game development studio could outsource the development of sound effects and musical scores to a company specializing in video game audio. This enables the studio to concentrate on other central elements of game development while guaranteeing top-notch audio that elevates the gaming experience. Outsourcing is especially appealing when focusing on budget, as hiring outside developers from regions with lower labor costs often makes financial sense.