The operando methodology is instrumental in catalysis science to assess catalyst structure, performance, dynamics, and kinetics under working conditions. This review analyzes the progress achieved mainly in thermal catalysis to combine different techniques and obtain the interdependency between catalyst structure, function, and reaction media. We analyze various materials of construction, reactor designs, contact types of the catalyst with the reactant, and modes of operation. We also highlight recent studies on combining these techniques and augmenting the obtained data by focusing on instrumentation and experimental design. We review the different reactors/cells used for different applications to understand the type of information received, limitations, and the design principles of these instruments. We provide our viewpoints on integrating spectroscopy, catalysis science, and reaction engineering; these advanced operandotechniques can offer a more comprehensive image of catalysts at work.