Stoichiometric theory includes multiple biological scales from elements to ecosystems, and allows the construction of robust mechanistic, predictive, and empirically testable models via rigorous chemical and physical laws. Experimental and fundamental evidence motivates the application of this microscopic approach to understand macroscopic phenomena. I will introduce a series of stoichiometric models and their novel dynamics that resolve some biological paradoxes and lead to new insights. Selected new mathematical development will be briefly described. “True” model validation will be presented in contrast to conventional methods with many freedoms. I will briefly mention my recent expansion on a new graduate program and research of data science and machine learning.