Bit Rot

Definitions

The gradual degradation of software over time even without code changes, caused by evolving dependencies, changing environments, and shifting assumptions. The code didn't change — the world around it did.
In plain English: When software slowly stops working even though nobody changed it — because the systems around it evolved and it didn't keep up.
Sometimes called software entropy or code decay. Bit rot is why a project that built fine six months ago now fails: a dependency published a breaking update, the OS patched a library, or a cloud provider deprecated an API version.
Example: 'We haven't touched the reporting service in a year and now it won't build. Classic bit rot — three dependencies have breaking changes.'
Source: synonym: software entropy