Credentials are one of the most vulnerable components of any software system, and yet, they're notoriously difficult to change. More specifically, developers are often loath to change credentials for two reasons: they either don't know how to do it safely, or they know that to do it safely, the entire system needs to be rebooted, which causes expensive downtime. Fortunately, things need not be this way! By applying a few basic strategies, any complex codebase can be designed to handle credential rotation with no redeployments and practically zero downtime. Additionally, even just going through the exercise can teach valuable lessons about system failure points and design weaknesses, which can better inform incident response.