What is really happening at an electrochemical interface? This is what I want to reveal. The interface is where the true magic of electrochemistry occurs and yet we know so little about it. The reason for our lack of understanding exists in the challenges that need to be overcome to probe an interface. It’s often buried underneath a gas or liquid phase making it difficult for traditional surface science techniques to be used, while those that can easily work in gas or liquid environments are often probing bulk properties. Many researchers have worked actively to overcome these challenges. Their effort has yielded significant advances to probe the interface under in situ and operando conditions. Ambient pressure X-ray photoelectron spectroscopy (APXPS) is one of the promising techniques developed that is capable of providing this information. This talk will introduce APXPS and how it has been utilized to provide new insight into the solid/gas electrochemical interface for PEM fuel cells. Then I will share the progress our group has made extending this technique into the tender X-ray regime (2 keV to 6 keV) to probe solid/liquid electrochemical interfaces under operando conditions. This will include several studies detailing our investigations to directly probe the electrochemical double layer (EDL), and insight into how platinum and oxide electrodes behave undergoing oxygen evolution reaction. Gaining new insight to guide the design and control of future electrochemical interfaces.