Add daily email for 2024-03-04

Why you need layers in your application code

source/_daily_emails/2024-03-04.md

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+---
+title: Why you need layers in your application code
+date: 2024-03-04
+permalink: archive/2024/03/04/why-you-need-layers-in-your-application-code
+tags:
+    - software-development
+    - software-architecture
+    - clean-code
+cta: ~
+snippet: |
+    Why should you make your code more robust and flexible by introducing layers into your code?
+---
+
+You need to add an integration with a new service or supplier to your application code.
+
+You should avoid writing code that interacts directly with that service or supplier - a.k.a tightly-coupled code.
+
+What if you change to a different service or supplier in the future?
+
+What if they release a new version of their API that includes breaking changes?
+
+If your code is tightly coupled to a single implementation, you'd need to rewrite the code, and there wouldn't be a way to easily switch from the old version to the new one.
+
+By introducing an adapter layer, you make your code more loosely coupled.
+
+You can have multiple implementations, with one for each different supplier, service, or version.
+
+You can have a consistent interface and API for every implementation, making them hot-swappable and making it easy to switch between different implementations.
+
+If you change supplier or they release a new version, you write a new implementation for it and switch when you're ready.
+
+Also, as every implementation satisfies a common interface, it's easy to make a fake implementation that you can use for testing.