I’d say a Development Manager or a Software development Manager.
Since development managers are responsible for leading teams of software developers and testers, they are the management function that would help Mary achieve this responsibility. Apart from the various duties that these people hold, they are also in charge of the logistics of their team, from training and promotions to hiring and firing. They own and oversee the entire development process and may be required to work with other people from other departments to determine software requirements.
