My first configuration management deployment was in 1998, using CFengine 1.5 to manage a fleet of Sun Ultra 2s. In the two decades since then, many things have changed but some constants remain. In this talk I’ll identify common patterns that have emerged, share some lessons learned, and relate a few funny stories. The astute observer will notice that there is still one year left until it’s exactly twenty years, and accordingly I will attempt to predict the future based on trendlines and tea leaves.