I don't think you know just how modular a Common Lisp environment is. Sure there is some hot reloading that sometimes works and you can change the value of variables, maybe even jump back and forth in your stack trace. Rarely does it do any of them as well as Common Lisp though, where the only thing that doesn't dynamically update when you change something is struct-instances and macros. Functions, variables/values, classes (including instances) can all change as you want it without restarting anything. When something goes wrong, like errors or exceptions, you can modify some code, restart some where on the stack, ignore it and continue execution, insert dummy value or insert a placeholder function.
Some form of interactivity with the debugger is common in my experience. The level of interactivity you get with Common Lisp is not.
