That's the one. Alas, the website precedes my so far best attempt at explaining what I've done, which is this paper, and I haven't had time to properly update the site since. And probably won't for some time: first give the presentation at Onward! in Pasadena next Wednesday, then finish writing the PhD thesis, then update the site.
Do you mean the stories of debugging the steaming pile of ... I mean my wonderful implementation of the language?
Or how to debug these kinds of system?
For the latter, I am actually very optimistic about making it possible to debug systems at a much higher and more meaningful level than currently, because you are making the high-level structure visible in the code instead of hand-compiling it down to some procedural implementation, with that hand-compiled procedural representation of your system being the thing that the the debugger sees.
With both the polymorphic write streams and the storage combinators being so highly composable, it becomes fairly easy to insert logging/instrumentation/debugging elements between the components of your system.
It is what it is ¯\_(ツ)_/¯