From energy-related transformations to organic syntheses, single-atom heterogeneous catalysts (SACs) are offering new prospects to tackle sustainability challenges. However, scarce design guidelines and poor mechanistic understanding due to a lack of discovery and operando characterization tools impede theirbroader development. This perspective offers a glimpse into how droplet-based microfluidic technologies mayhelp solve both of these issues, and provides technical considerations for platform design to systematically fabricate SACs and study them under operational conditions during liquid-phase organic syntheses.