Explore a framework for sandboxing and restricting OCaml programming language features to automate grading of programming exercises at scale. Learn about disabling specific language and library features, implementing a mock IO system for controlled testing of IO-related exercises, and ensuring security measures to maintain trusted automatic grading without manual verification. Discover how this approach can enhance effective teaching of OCaml, with insights from Max Lang and Nico Petzendorfer presented at OCaML'23. Access the publicly available source code implementation on GitHub to further understand and potentially apply these techniques in educational settings.