Recorded myself doing a mock system design round and watching it back was brutal, but it actually worked

Practiced system design out loud alone for weeks and felt fine about it. Then I recorded one session on my phone and watched it back — turns out I trail off mid-sentence constantly and default to "it depends" instead of actually picking a tradeoff. Painful to watch but I fixed both within a week just from seeing it. Cheap thing to try if you think you're ready and haven't actually reviewed the footage.