Traditionally GADT's are used for lightweight tasks as the code complexity increases quite. I will be arguing that this is mostly a lack of common "design patterns" and maybe some tools.
The talk will go through describing what you can fundamentally do with GADT's, how you should think about them and a general technique to mimick dependent types in OCaml,
Hopefully by the end, a show case of a proposal for the Michelson interpreter.