The development leader's job is to work with the customer in identifying the solution requirements. Once the requirements are understood, the development leader will divide the work among various developers and solution experts for design. Once the design is complete, the development leader will review the solution design with the customer and then commence into development and testing.
The development leader's job is to help the customer visualize the solution through creating a design and realize the solution via delivery. The development leader must with work with his developers to ensure on-time delivery of tasks and help to remove any blockers or issues that may impede development progress. It is up to the development leader's leadership skills and vision which lead to the customer's success.