diff --git a/SUMMARY.md b/SUMMARY.md
index ae7eb6f..66314ba 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -18,6 +18,7 @@
 
 ## REST APIs
 
+* [Introduction](core-principles/introduction.md)
 * [OpenAPI Specification](core-principles/openapi-specification.md)
 * [API Design Platform](core-principles/apiary.md)
 * [Design Maturity](core-principles/design-maturity.md)
@@ -62,3 +63,5 @@
 
 ## Kafka
 
+* [Introduction](kafka/introduction.md)
+
diff --git a/core-principles/introduction.md b/core-principles/introduction.md
new file mode 100644
index 0000000..e69de29
diff --git a/kafka/introduction.md b/kafka/introduction.md
new file mode 100644
index 0000000..65a172c
--- /dev/null
+++ b/kafka/introduction.md
@@ -0,0 +1,2 @@
+Apache Kafka at adidas
+