While lead architect of the new st. peter's project, what was michelangelo's design contribution to the project?

Michaelangelo's design contribution to the St. Peter project was the chancel end (the "Easter End") placed on a huge dome at the center of the Basilica. His work is best appreciated from a distance because he played with geometric patterns that emphasized the design that he created in relation to the design of the lead architects that were also working on the Basilica.