Chemical reactions on heterogeneous surfaces present numerous scientific and engineering challenges across varying spatiotemporal scales. For example, a single molecule may reactive at an active site containing only a few atoms (sub-nm) before desorbing and diffusing away to a similar active site many hundreds of micrometers away where it may react again to form unwanted byproducts and decrease overall reaction selectivity. Meanwhile, heterogeneous catalysts ideally remain stable for many hours or days, but frequently they restructure, segregate, and sinter. All of these processes complicate the clean picture of how chemical reactions occur under real conditions. To this end, we are actively constructing new observational tools to image and monitor chemical processes in operando. These tools consist of new spectroscopic techniques, microscopy methods, and novel nanoscale sensors that will provide insight into the dynamic landscape that occurs at the surfaces of heterogeneous catalysts.