Besides speculative personal inventions, what did patrons like Ludovico Sforza primarily employ Da Vinci for?

Military engineering, stage machinery, and architectural projects

Leonardo da Vinci was actively employed as a practicing engineer by powerful patrons throughout his career, notably Ludovico Sforza in Milan and later Cesare Borgia and King Francis I of France. Although his personal interests lay in concepts like human flight, the demands and priorities of his employers often dictated his engineering focus. Therefore, the commissions he undertook successfully centered on areas of immediate utility to the court or military structure. These practical applications included designing and overseeing military engineering efforts, creating elaborate stage machinery necessary for courtly festivals and spectacles, and contributing to significant architectural projects.