Microbial bioelectrochemical systems (BES) represent a promising platform for sustainable biochemical production by leveraging microbial electrocatalysis. These systems utilize electrical energy to drive microbial metabolic processes, enabling the recovery of CO₂ into valuable organic molecules such as methane, acetate, ethanol, and other biochemicals. This approach aligns with global efforts to mitigate greenhouse gas emissions and create circular carbon economies. The advancement of BES technology requires both scale-down and scale-up strategies to ensure feasibility and scalability. Scale-down approaches focus on optimizing operational parameters, enhancing electron transfer efficiencies, and understanding microbial community dynamics under controlled conditions. Scale-up efforts address the challenges of maintaining system stability, energy efficiency, and economic viability in larger, industrial-scale operations. Together, these strategies bridge the gap between fundamental laboratory research and real-world applications, positioning microbial BES as a key technology for sustainable biochemical production and captured carbon utilization.