Red Flag
Noun · Slang & Abbreviations
Definitions
A warning sign that something is risky, unhealthy, or likely to become a larger problem. In engineering slang, red flags are the clues teams often recognize early and regret ignoring later.
In plain English: A warning sign that something may be risky or problematic.
Example: "The absence of rollback steps was a red flag from day one, even before the first rehearsal showed how brittle the migration path really was."