diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 939e534..1dce611 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -3,6 +3,12 @@
 We'd love to accept your patches and contributions to this project. There are
 just a few small guidelines you need to follow.
 
+## Development Principles (for Googlers)
+
+There are a few principles for developing or refactoring the service
+implementations. Read the [Development Principles
+Guide](./docs/development-principles.md).
+
 ## Contributor License Agreement
 
 Contributions to this project must be accompanied by a Contributor License