Recombinant adeno-associated viruses are a promising gene therapy, with several therapeutics on the market in the United States. As we continue to industrialize manufacturing of these viral vectors, we strive to improve productivity and yield. To this end, we investigated a novel transfection reagent to improve the genomic titer of adeno-associated virus 8. Using a miniaturized automated 250 mL scale bioreactor system, we generated models of genomic and capsid titer from two multivariate design of experiments; one centered around bioprocess conditions, and another based on the transfection conditions. Using the optimized setpoints returned from these models, we improved our viral genome titer out of the bioreactor to beyond 1 × 10 ¹² vg/mL; to our knowledge the highest genomic titer reported from an upstream process utilizing HEK293 cells. When we applied these setpoints to six serotypes carrying a unique viral payload, five of the six returned higher genomic titers than the control condition, but were all below the titer of the vector used in our optimization studies. These data suggest that the choice of transfection reagent is a major factor in viral titer and percent full capsids, and that transfection conditions are serotype and payload specific.