While Hydrogen Embrittlement (HE) has been extensively studied in different metallic materials, many fundamental questions remain open and need to be addressed to guide the design of commercial alloys with improved resistance. Characterizing HE is in itself a challenging task: mechanical or image analysis has to be performed with continuous charging to guarantee the presence of diffusible hydrogen within the microstructure, however hydrogen cannot be easily detected and therefore its distribution is often unknown. We have recently developed a setup that allows us to perform micro-mechanical testing with continuous hydrogen charging in-situ in SEM. The setup consists of an electro-chemical cell that can charge a sample from one surface while leaving a pristine objective surface intact for micro-structural and mechanical analysis. The setup is compatible with high-vacuum systems and with commercial picoindenters such that concurrent charging, imaging and mechanical testing can be performed. In this talk we will present recent results where we employ such highly integrated approach to study hydrogen embrittlement in steels and high entropy alloys. We will explore how different H diffusion pathways throughout different microstructures can be designed to improve HE resistance.