A minifier moved one line and took production down for four days
What happened
Object shorthand inside a call the bundler chose to inline survived relocation un-expanded. The deployed bundle then referenced a variable that no longer existed. It failed only in the production build, and only on the email path — so every local test passed and the error looked like a bad deploy.
What changed
We now reproduce in a production build before calling anything fixed, and grep the compiled chunks for the pattern rather than trusting the source. At known-risky call sites we write arguments out in full instead of using shorthand.