A major obstacle in the development of industrial catalysts is the scalability of both catalyst performance and synthesis. While utilizing pilot-scale test reactors allows for a direct transfer from the development stage to the application, it comes at the cost of flexibility. The amount of catalyst required in a pilot-scale test reactor often surpasses the yields of novel synthesis procedures, requiring extensive scale-up efforts. Here, pilot-scale reactors are combined with small lab-scale reactors, using the example of oxidation of o-xylene to phthalic anhydride.