It is tough to figure why Erlang or Elixir code is failing, or how unknown software is working. When confronted with an unusual error, we might search for it in the code, which often gives multiple results, so we resort to guessing. We might also decide to trace with tools like dbg or recon, but here we need to guess, which functions to trace. I would like to show you a different approach, where the first step is to trace multiple modules or even whole apps. Then you can query, analyse, process and even execute the collected traces. The tool itself is so simple, that you will be able to use it instantly. It is also battle-proven, as I have used it numerous times to debug the MongooseIM project, which I am leading. Limit unnecessary guesswork and have more time for creative work.