Protein sequences inhabit a discrete set in macromolecular space with incredible capacity to treat human disease. Despite our ability to program and manipulate protein sequences, the vast majority of protein development efforts are still done heuristically without a unified set of guiding principles. This article highlights work in understanding biophysical stability and function of proteins, developing new biophysical measurement tools and building high-throughput screening platforms to explore functional protein sequences. We highlight two primary areas. First, molecular biomechanics is a subfield concerned with the response of proteins to mechanical forces, and how we can leverage mechanical force to control protein function. The second subfield investigates the use of polymers and hydrogels in protein engineering and directed evolution in pursuit of new molecular systems with therapeutic applications. These two subdisciplines complement each other by shedding light onto sequence and structural features that can be used to impart stability into therapeutic proteins.