If you’ve ever built an app that talks to some external service, you know how painful it can be when the business team suddenly says: “Hey, we need to change our technology from ChatGPT API to Claude API”. That usually means ripping apart half your codebase just to swap a library. Not fun. That’s where technology-agnostic design patterns come in. The idea is simple: keep your business logic (the what) separate from the technology-specific implementation (the how).