Cells are the greatest known molecular engineers, able to build extraordinary microscale mechanical devices and information processing systems that greatly surpass our own capabilities and know-how. How complex cellular behaviors and functions emerge from the organization and control of the cell’s macromolecular hardware is a fundamental question that lies at the interface between systems biology, cell biology and biochemistry. My group is taking a reverse-engineering approach in which we treat cell behavior as the output a microscopic robot driven by patterns of activity acting on different configurations of a common set of molecular components. We apply this approach to chart the systems biology that governs cell behavior in a range of diverse systems, ranging from migration and adhesion in metazoan cells to elaborate animal-like behaviors of complex single-celled protozoans. Long term, we aim to apply this knowledge to explore new frontiers in synthetic biology that rewire cell motility and behavior and to engineer in vitro biochemical systems that emulate the extraordinary capabilities of living cells.