The successful candidate will apply technical expertise in upstream processing (USP)-including seed train optimization, mammalian cell culture (HEK293/HEK293T), large-scale transient transfection, and bioreactor scale-up-to ensure processes are robust, scalable, and phase-appropriate for GMP manufacturing. Perform development and optimization of upstream processes, including seed train expansion, suspension mammalian cell culture (HEK293/HEK293T), plasmid transient transfection optimization, and feed batch/perfusion bioprocessing in stir-tank and rocker bioreactors.