A manufacturing strategy from Portugal’s iBET and collaborators proposes “rapid manufacturing” for CAR T-cell products by limiting ex vivo expansion to three days or less. The approach is intended to shift the manufacturing goal from maximizing cell numbers to producing fewer but “fitter” naïve and stem cell-like memory T cells. The report frames the central issue as vein-to-vein time: delays can leave patients deteriorating before their autologous product is ready. Conventional expansion timelines often exhaust cells toward a more differentiated state. The authors argue that shortening expansion requires automation and sensor-equipped digital control to preserve reproducibility and enable decentralized production models at hospital sites, positioning process engineering and monitoring as the bottleneck solution.