Junior dev asking "purely theoretically" is the biggest red flag since that time someone pushed directly to main on a Friday at 4:55 PM. The senior knows exactly what happened—that API key is already swimming in the commit history, probably in a public repo, and some bot in Russia has already spun up 47 crypto miners on your AWS account. The senior's stare says it all: "I've seen this movie before, and it doesn't end with git revert ." You can't just delete the commit and call it a day—that key is burned. Time to rotate credentials, check the audit logs, explain to the security team why the monthly bill just went from $200 to $12,000, and have a very uncomfortable Slack conversation with your manager. Pro tip: git filter-branch and BFG Repo-Cleaner can scrub history, but if it's already pushed to a public repo, that secret is out there forever. Just rotate it and add .env to your .gitignore like you should've done in the first place.