Mostly I have an elixir codebase, and for doing nontrivial stuff it can read the whole file to have sufficient context, so I can:

• mark some lines like an ugly function and say “refactor this to idiomatic elixir” (cmd+K) and it does quite perfectly
• in a module cmd-k and task it to write a function that does a particular thing, like in a ecto context module “write a function that lists me all users that XYZ” and it does - and since my module already contains proper @doc and @spec everywhere (also AI-generated), it adds these right away
• see some code maybe an algorithm that you try to understand: mark the lines and “explain me what this does and why”
• see some error (intellisense or terminal) and hit the “auto debug” button, where it hunts down where the error comes from and why - does even propose a fix like 50% of the time, but at least ends up in the right location in general

… just ontop of my head