This case study explores the selective partial reduction of esters to aldehydes, a process known for its challenges due to fast reaction kinetics, high exothermicity, and unstable intermediates. Traditional batch methods demand stringent temperature control and slow dosing of DIBAL-H at cryogenic conditions (-70 to -50 ºC), often resulting in over-reduction to alcohols. Here, we present a pilot-scale solution using continuous flow chemistry, achieving outputs of 0.72–1.2 kg/h. By incorporating 3D metal printing for flow reactors, heat exchangers, and static mixers, we demonstrate a scalable and efficient approach to managing this highly reactive process.