Explore a state-of-the-art Domain-Specific Language (DSL) implementation in OCaml through this 20-minute conference talk from OCaML'23. Gain insights into advanced practices and concrete examples based on the Catala compiler, a DSL for implementing algorithms defined in law. Learn about lesser-known techniques like the use of row type variables through object types, which are accepted among experienced OCaml developers but lack visibility and documentation. Discover how Louis Gesbert and Denis Merigoux leverage these practices in their work with the Catala compiler, providing valuable experience reports and showcasing modern DSL compiler architecture in OCaml.