diff --git a/core/design.md b/core/design.md
index e838769dd97..bdd3f5d46b0 100644
--- a/core/design.md
+++ b/core/design.md
@@ -1,8 +1,8 @@
 # General Design Considerations
 
 Since you only need to describe the structure of the data to expose, API Platform is both
-[a "design-first" and "code-first"](https://swagger.io/blog/api-design/design-first-or-code-first-api-development/)
-API framework. However, the "design-first" methodology is strongly recommended: first you design the
+[a "design-first" and "code-first"](https://swagger.io/blog/code-first-vs-design-first-api/) API
+framework. However, the "design-first" methodology is strongly recommended: first you design the
 **public shape** of API endpoints.
 
 To do so, you have to write a plain old PHP object (POPO) representing the input and output of your
diff --git a/core/serialization.md b/core/serialization.md
index 4cbcf3c61de..0a0659ccf4f 100644
--- a/core/serialization.md
+++ b/core/serialization.md
@@ -308,22 +308,22 @@ class Book
 # api/config/api_platform/resources/Book.yaml
 App\ApiResource\Book:
     normalizationContext:
-        groups: ['get']
+        groups: ["get"]
     operations:
         ApiPlatform\Metadata\Get: ~
         ApiPlatform\Metadata\Get: ~
         ApiPlatform\Metadata\Patch:
             normalizationContext:
-                groups: ['patch']
+                groups: ["patch"]
 
 # The YAML syntax is only supported for Symfony
 # api/config/serializer/Book.yaml
 App\ApiResource\Book:
     attributes:
         name:
-            groups: ['get', 'patch']
+            groups: ["get", "patch"]
         author:
-            groups: ['get']
+            groups: ["get"]
 ```
 
 ```xml
@@ -452,16 +452,16 @@ class Book
 # api/config/api_platform/resources/Book.yaml
 App\ApiResource\Book:
     normalizationContext:
-        groups: ['book']
+        groups: ["book"]
 
 # The YAML syntax is only supported for Symfony
 # api/config/serializer/Book.yaml
 App\ApiResource\Book:
     attributes:
         name:
-            groups: ['book']
+            groups: ["book"]
         author:
-            groups: ['book']
+            groups: ["book"]
 ```
 
 </code-selector>
@@ -597,18 +597,18 @@ class Person
 # api/config/api_platform/resources/Person.yaml
 App\ApiResource\Person:
     normalizationContext:
-        groups: ['person']
+        groups: ["person"]
     denormalizationContext:
-        groups: ['person']
+        groups: ["person"]
 
 # The YAML syntax is only supported for Symfony
 # api/config/serializer/Person.yaml
 App\ApiResource\Person:
     attributes:
         name:
-            groups: ['person']
+            groups: ["person"]
         parent:
-            groups: ['person']
+            groups: ["person"]
 ```
 
 </code-selector>
@@ -870,18 +870,18 @@ App\Entity\Greeting:
     operations:
         ApiPlatform\Metadata\GetCollection:
             normalizationContext:
-                groups: 'greeting:collection:get'
+                groups: "greeting:collection:get"
 
 # The YAML syntax is only supported for Symfony
 # api/config/serializer/Greeting.yaml
 App\Entity\Greeting:
     attributes:
         id:
-            groups: 'greeting:collection:get'
+            groups: "greeting:collection:get"
         name:
-            groups: 'greeting:collection:get'
+            groups: "greeting:collection:get"
         sum:
-            groups: 'greeting:collection:get'
+            groups: "greeting:collection:get"
 ```
 
 </code-selector>
@@ -932,18 +932,18 @@ class Book
 # api/config/api_platform/resources/Book.yaml
 App\ApiResource\Book:
     normalizationContext:
-        groups: ['book:output']
+        groups: ["book:output"]
     denormalizationContext:
-        groups: ['book:input']
+        groups: ["book:input"]
 
 # The YAML syntax is only supported for Symfony
 # api/config/serializer/Book.yaml
 App\ApiResource\Book:
     attributes:
         active:
-            groups: ['book:output', 'admin:input']
+            groups: ["book:output", "admin:input"]
         name:
-            groups: ['book:output', 'book:input']
+            groups: ["book:output", "book:input"]
 ```
 
 </code-selector>
diff --git a/core/state-providers.md b/core/state-providers.md
index a50db2766c3..5da3e85c78e 100644
--- a/core/state-providers.md
+++ b/core/state-providers.md
@@ -435,13 +435,13 @@ use the following snippet:
 services:
     # ...
     App\State\BlogPostProvider:
-        tags: [ 'api_platform.state_provider' ]
+        tags: ["api_platform.state_provider"]
 
 # api/config/services.yaml
 services:
     # ...
     App\State\BookRepresentationProvider:
         arguments:
-            $itemProvider: '@api_platform.doctrine.orm.state.item_provider'
-        tags: [ 'api_platform.state_provider' ]
+            $itemProvider: "@api_platform.doctrine.orm.state.item_provider"
+        tags: ["api_platform.state_provider"]
 ```