Predictably interfacing biomolecules with solids is the key for drug delivery, enzyme immobilization, implant biofunctionalization, and biochemical-sensors plus cell behavior and remineralization. Highly specific interactions controlled by proteins facilitate explicit mineral formation with intricate supramolecular architectures in nature. Mimicking natural proteins, engineered short polypeptides, aka GEPIs, are ubiquitous molecular tools in addressable functionalization of solid interfaces. Simplicity of peptide sequences and functional domains offer latent means for interrogating intermolecular forces towards tailored molecular recognition and signal transduction. Using biocombinatorially selected and rationally designed peptides, our team has been demonstrating organized biomolecular architectures as potent utility in nano-electronics/photonics and molecular-medicine. Starting from biological fundamentals, this talk will present practical utility of GEPIs in vast array of implementations encompassing many of the developments in hybrid materials fabrication, all under biologically viable conditions of water, pH7, RT, and atmospheric conditions, during the last 2 decades. Supported by NSF-DMREF and Amazon-Catalyst Programs.