Upon discovering that sensitive information or secrets have been exposed in a public git repository, developers should take immediate action to mitigate potential damage. The initial step involves revoking the compromised secret to prevent exploitation, followed by notifying relevant parties, especially if the secret pertains to an organization. Simply deleting the file or making the repository private is insufficient, as git history retains changes and public APIs can expose leaks. A more thorough approach involves permanently removing evidence of the leak by using tools like BFG Repo-Cleaner to cleanse the repository's history, though this can disrupt workflows if not done carefully. Additionally, monitoring access logs is crucial to detect any further security breaches. Moving forward, implementing robust security practices, such as adopting tools like GitGuardian that monitor public repositories for leaks and reviewing API best practices, is essential to prevent future exposure of sensitive data.