TL;DR: for a cheap Node.js uptime dashboard, add custom metrics to the internal admin panel when the decision is whether to keep or roll back a logistics pricing rule. An external API health probe can prove that the quote service answers, but it cannot prove that the new rule produces valid prices. Ship behind a flag, label every outcome with a bounded rule version, and make rollback depend on quote failures, suspicious price outcomes, and fallback use. Choice Detects bad pricing D...