The Unity 3D developer will be responsible for scoping work accurately and adhering to time and cost constraints. They should stay updated on the latest technologies and share advancements with team members. The developer will propose creative solutions, communicate them effectively, and be attentive to performance optimization. Collaboration within cross-functional and client teams is essential, along with strong communication skills and a passion for game development. The developer will be involved in the design and implementation of game systems and mechanics.