Ha, exactly. A green dashboard is marketing until someone can audit the numbers behind it. If the only proof of what ran is the vendor's own badge, you don't have observability, you have trust with extra steps. Flags tell you what was switched on. Receipts tell you what it cost. And only one of those wins a billing argument. The article makes the same point from the other side: the first 10 minutes of a system design interview are the whole interview, because the interviewer is deciding whether you can scope a problem or just perform one. I wrote the Frontend Interview Playbook around exactly that: bittalk.gumroad.com/l/frontend-interview-playbook