After adding one environment variable in values-prod.yaml, production pods lost six others defined in the chart's defaults, including the database host. Helm deep-merges maps but replaces lists entirely. How we spotted it with helm template diffs and restructured values so overrides merge.
After a configuration refactor, a bot meant for the testnet connected to the production exchange with test parameters: order sizes ten times larger than production limits. A risk check caught it after four orders. This postmortem covers how environment selection failed and the guardrails we added.
A summary of Cloudflare's official postmortem for the November 18, 2025 outage: a database permission change doubled a generated feature file, which crossed a hard limit and crashed the proxy. Plus the lessons we are applying to our own config pipelines.