practiced system design out loud alone in my car for two weeks straight and it fixed more than any diagram ever did

Spent two weeks talking through system design problems out loud during my commute, no whiteboard, no notes, just narrating the tradeoffs to an empty car. Felt ridiculous the first few days. Turns out the thing that actually breaks in real interviews is explaining reasoning smoothly, not knowing the components, and I was only ever practicing the second part before. First mock after doing this felt like a completely different skill.