The engineering of enzymatic bioprocesses for biomass energy production offers a sustainable approach to renewable energy sources. This chapter highlights recent developments in optimizing enzymatic conversion of biomass into bioethanol, biogas, and biodiesel. The key strategies include genetic modification and directed evolution to enzyme efficiency in breaking down cellulose, hemicellulose, and lignin. Protein engineering has led to robust enzyme variants capable of withstanding extreme industrial conditions, improving process resilience. Integration of these enzymes into bioreactors, including continuous-flow and immobilized enzyme systems, has significantly increased scalability and efficiency. Systems biology and metabolic engineering have further optimized microbial strains for higher energy yields. Economic and environmental considerations are critical, as enzymatic bioprocessing reduces costs of and greenhouse gas emissions compared to fossil fuels. Advances in enzyme production and recovery techniques enhance the feasibility for large-scale applications. Overall, engineering innovations in enzyme technology, reactor design, and process optimization are essential to overcoming current challenges and promoting broader adoption of enzymatic biomass conversion in the energy sector.