In recent years, light-induced hydrogen atom transfer (HAT) presented itself as a versatile strategy for the late-stage functionalization of C(sp )-H bonds without involving transition-metal catalysis or strong oxidants. In HAT, the photoexcited catalyst abstracts a hydrogen atom resulting in the formation of reactive radical species, which are exploited for highly selective functionalization. To achieve this selectivity, careful tuning of the steric and electric properties of the HAT photocatalyst and substrate has to take place. Among the limited selection of photocatalysts promoting HAT, arguably the most versatile HAT photocatalyst is the decatungstate anion, which found application in a wide range of transformations, including alkylation, arylation, acylation, 10 amination , fluorination, trifluoromethylation, sulfinylation and oxygenation (Scheme 1A). Despite the potential of TBADT for synthetic applications, the adoption of photocatalytic HAT in industrial processes is still limited. To understand this, one has to consider that while catalyst cost and removal or recycling are minor concerns in demonstrating a new synthetic method, these aspects become major focal points in the transition from small scale (e.g., required in medicinal chemistry and academia) to large-scale production (Scheme 1B-C). Therefore, among the main hurdles hindering its adoption, the primary concerns are the questions surrounding the ability to scale up photocatalytic HAT reactions paired with the need to recycle the catalyst and the requirement to purify the product. The former concern about scalability has been addressed in recent years when continuous-flow chemistry systems proved to be the answer to the scale-up needs of photochemical reactions, as was highlighted in several examples of large-scale photochemical reactions carried out in continuous-flow systems. For the removal of the catalyst, organic solvent nanofiltration (OSN) could be a suitable strategy for catalyst recovery in continuous-flow systems. OSN is a membrane-based process where selective separation of the species present in solution is obtained based on their size. Molecules smaller than the so-called molecular weight cut-off (MWCO) of the membrane will pass through the membrane, while species larger than the MWCO are selectively retained. Typical MWCO values for commercial OSN membranes range from 150 to 1000 Da, thus making them ideal for the selective separation between homogeneous catalysts having a large molecular weight, such as TBADT, and smaller reaction products. Additionally, OSN has the distinct advantage of low energy requirements since phase transitions such as evaporation are avoided in this separation technique. The absence of thermal transitions also removes the issue of thermal stress for the recovered catalyst, which is present in other recovery techniques. The work of Livingston and co-workers highlighted the performance of OSN with commercial membranes for the recovery of a homogeneous catalyst in Heck couplings performed in continuous flow. demonstrated the use of OSN to recover homogeneous catalyst complexes in a hydroformylation reaction. Similarly, O'Neal and Jensen implemented a small-scale custom OSN unit in an automated setup performing ring-closing metathesis with a recycled secondgeneration Hoveyda-Grubbs catalyst. Although recent works showcased the potential of OSN in flow chemistry, they also highlighted the challenges of catalyst deactivation and membrane fouling.