This chapter focuses on metabolic and genetic engineering approaches to improve the enzymatic conversion of lignocellulosic biomass for biofuel and biochemical production. By modifying metabolic pathways and engineering enzymes for enhanced activity, stability, and substrate specificity, these strategies address the challenges posed by the complex structure of lignocellulose. The chapter highlights the application of CRISPR/Cas technology for precise genome editing, the optimization of microbial strains to utilize hexose and pentose sugars efficiently, and the development of microbes for consolidated bioprocessing. Additionally, advancements in enzyme engineering techniques to improve performance under industrial conditions are discussed. Emerging synthetic and systems biology trends offer insights into future possibilities for further improving lignocellulosic biomass conversion.