tags: #publish links: [[Software Architecture]] created: 2023-04-17 Mon --- # Hyrum's Law - the interface runs deeper than you think https://www.hyrumslaw.com/ > At sufficient scale, your contracts don't matter, all observable behaviours of your system will be depended on by somebody Could be summarised as **The interface runs deeper than you think!** - Implicit interfaces - the actual behaviour - Implementation does matter, as well as interfaces - Your impl isn't private if it has observable behaviours (e.g. timing, performance, error handling) - This is a slow creep thing and changes will reveal surprises