… Hector Castillo, current engineering Ph.D. students at Yale, and Mitch Guillaume, a former classmate when the three of them attended MIT. Floe is building a cost-effective and … Hector Castillo, current engineering Ph.D. students at Yale, and Mitch Guillaume, a former classmate when the three of them attended MIT. Floe is building a cost-effective and … Hector Castillo, current engineering Ph.D. students at Yale, and Mitch Guillaume, a former classmate when the three of them attended MIT. Floe is building a cost-effective and …