Biocatalysis has become a crucial tool in chemical synthesis, enabling the production of complex molecules with high activity, selectivity, and low environmental impact. Key advancements in protein engineering, bioinformatics, recombinant technology, and DNA sequencing have accelerated the field. This tutorial review explores enzyme engineering strategies and high-throughput screening methods used to discover and develop enzymes for synthetic applications. Landmark developments in biocatalysis are discussed, highlighting their diverse applications in pharmaceutical, agricultural, food, and chemical industries. The design and development of artificial biocatalytic cascades are also examined. Enzymes are biological catalysts that accelerate chemical reactions within biological systems. Their active site pocket enables high reaction rates and selectivity by precisely positioning substrates through weak interactions. The field of enzymology has advanced through molecular biology, bioinformatics, and high-throughput screening, leading to widespread synthetic applications of enzymes in biocatalysis. The term 'biocatalyst' can refer to purified enzymes, crude mixtures, whole-cell systems, or combinations thereof. The first known enzyme, diastase, was discovered in 1833 by French chemists. The 1946 Nobel Prize in Chemistry recognized the work of Sumner, Northrop, and Stanley, who proved that enzymes are proteins. The Lock and Key model and the Induced Fit Model have been pivotal in understanding enzyme-substrate interactions. Mechanistic and kinetic studies, along with developments in X-ray crystallography, have elucidated enzyme structures and mechanisms. Enzyme engineering methodologies, such as rational design, directed evolution, and semi-rational design, have been developed to improve enzyme properties. Rational design involves precise amino acid sequence changes, while directed evolution uses random mutagenesis and screening to identify optimal variants. Semi-rational design combines rational and evolutionary approaches to create smaller, more efficient libraries. High-throughput screening (HTS) and ultrahigh-throughput screening (uHTS) are essential for identifying improved enzyme variants. Spectrophotometric, colorimetric, and fluorescence screening methods are used to detect enzyme activity. These methods enable the identification of genetic variants with desired properties, from millions of possibilities. In synthetic chemistry, biocatalysts are used for asymmetric synthesis, kinetic resolution, and deracemisation. Enzymes such as P450 monooxygenases, transaminases, and imine reductases are crucial for producing chiral compounds. Directed evolution has been used to improve enzyme activity and selectivity, leading to more efficient biocatalysts. The application of biocatalysis in synthetic chemistry is growing, with enzymes now routinely considered alongside other asymmetric catalysts. Biocatalysis offers advantages such as mild reaction conditions and reduced use of precious metals. The development of biocatalytic methods for asymmetric synthesis, dynamic kinetic resolution, and deracemisation remains a vibrant research area.Biocatalysis has become a crucial tool in chemical synthesis, enabling the production of complex molecules with high activity, selectivity, and low environmental impact. Key advancements in protein engineering, bioinformatics, recombinant technology, and DNA sequencing have accelerated the field. This tutorial review explores enzyme engineering strategies and high-throughput screening methods used to discover and develop enzymes for synthetic applications. Landmark developments in biocatalysis are discussed, highlighting their diverse applications in pharmaceutical, agricultural, food, and chemical industries. The design and development of artificial biocatalytic cascades are also examined. Enzymes are biological catalysts that accelerate chemical reactions within biological systems. Their active site pocket enables high reaction rates and selectivity by precisely positioning substrates through weak interactions. The field of enzymology has advanced through molecular biology, bioinformatics, and high-throughput screening, leading to widespread synthetic applications of enzymes in biocatalysis. The term 'biocatalyst' can refer to purified enzymes, crude mixtures, whole-cell systems, or combinations thereof. The first known enzyme, diastase, was discovered in 1833 by French chemists. The 1946 Nobel Prize in Chemistry recognized the work of Sumner, Northrop, and Stanley, who proved that enzymes are proteins. The Lock and Key model and the Induced Fit Model have been pivotal in understanding enzyme-substrate interactions. Mechanistic and kinetic studies, along with developments in X-ray crystallography, have elucidated enzyme structures and mechanisms. Enzyme engineering methodologies, such as rational design, directed evolution, and semi-rational design, have been developed to improve enzyme properties. Rational design involves precise amino acid sequence changes, while directed evolution uses random mutagenesis and screening to identify optimal variants. Semi-rational design combines rational and evolutionary approaches to create smaller, more efficient libraries. High-throughput screening (HTS) and ultrahigh-throughput screening (uHTS) are essential for identifying improved enzyme variants. Spectrophotometric, colorimetric, and fluorescence screening methods are used to detect enzyme activity. These methods enable the identification of genetic variants with desired properties, from millions of possibilities. In synthetic chemistry, biocatalysts are used for asymmetric synthesis, kinetic resolution, and deracemisation. Enzymes such as P450 monooxygenases, transaminases, and imine reductases are crucial for producing chiral compounds. Directed evolution has been used to improve enzyme activity and selectivity, leading to more efficient biocatalysts. The application of biocatalysis in synthetic chemistry is growing, with enzymes now routinely considered alongside other asymmetric catalysts. Biocatalysis offers advantages such as mild reaction conditions and reduced use of precious metals. The development of biocatalytic methods for asymmetric synthesis, dynamic kinetic resolution, and deracemisation remains a vibrant research area.