diff --git a/callback/src/main/java/com/iluwatar/callback/LambdasApp.java b/callback/src/main/java/com/iluwatar/callback/LambdasApp.java
new file mode 100644
index 000000000..19dd17eae
--- /dev/null
+++ b/callback/src/main/java/com/iluwatar/callback/LambdasApp.java
@@ -0,0 +1,19 @@
+package com.iluwatar.callback;
+
+/**
+ *
+ * This example generates the exact same output as {@link App} however the callback has been
+ * defined as a Lambdas expression.
+ *
+ */
+public class LambdasApp {
+
+  /**
+   * Program entry point
+   */
+  public static void main(String[] args) {
+    Task task = new SimpleTask();
+    Callback c = () -> System.out.println("I'm done now.");
+    task.executeWith(c);
+  }
+}
diff --git a/callback/src/test/java/com/iluwatar/callback/AppTest.java b/callback/src/test/java/com/iluwatar/callback/AppTest.java
index 67046a175..28d6eaa1c 100644
--- a/callback/src/test/java/com/iluwatar/callback/AppTest.java
+++ b/callback/src/test/java/com/iluwatar/callback/AppTest.java
@@ -36,4 +36,22 @@ public class AppTest {
     assertEquals("Callback called twice", new Integer(2), callingCount);
 
   }
+
+  @Test
+  public void testWithLambdasExample() {
+    Callback callback = () -> callingCount++;
+
+    Task task = new SimpleTask();
+
+    assertEquals("Initial calling count of 0", new Integer(0), callingCount);
+
+    task.executeWith(callback);
+
+    assertEquals("Callback called once", new Integer(1), callingCount);
+
+    task.executeWith(callback);
+
+    assertEquals("Callback called twice", new Integer(2), callingCount);
+
+  }
 }
diff --git a/event-driven-architecture/etc/class_diagram.png b/event-driven-architecture/etc/class_diagram.png
deleted file mode 100644
index 69560e1f4..000000000
Binary files a/event-driven-architecture/etc/class_diagram.png and /dev/null differ
diff --git a/event-driven-architecture/etc/eda.png b/event-driven-architecture/etc/eda.png
new file mode 100644
index 000000000..38c433a40
Binary files /dev/null and b/event-driven-architecture/etc/eda.png differ
diff --git a/event-driven-architecture/etc/eda.ucls b/event-driven-architecture/etc/eda.ucls
new file mode 100644
index 000000000..4ddb8b20c
--- /dev/null
+++ b/event-driven-architecture/etc/eda.ucls
@@ -0,0 +1,196 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<class-diagram version="1.1.9" icons="true" automaticImage="PNG" always-add-relationships="true" generalizations="true" 
+  realizations="true" associations="true" dependencies="true" nesting-relationships="true" router="FAN">  
+  <class id="1" language="java" name="com.iluwatar.eda.model.User" project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/model/User.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="937" y="618"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="2" language="java" name="com.iluwatar.eda.handler.UserUpdatedEventHandler" 
+    project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/handler/UserUpdatedEventHandler.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="936" y="90"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="3" language="java" name="com.iluwatar.eda.handler.UserCreatedEventHandler" 
+    project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/handler/UserCreatedEventHandler.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="101" width="200" x="41" y="37"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <interface id="4" language="java" name="com.iluwatar.eda.framework.Message" project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/Message.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="298" y="189"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <interface id="5" language="java" name="com.iluwatar.eda.framework.Handler" project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/Handler.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="532" y="89"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="6" language="java" name="com.iluwatar.eda.framework.EventDispatcher" project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/framework/EventDispatcher.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="613" y="292"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="7" language="java" name="com.iluwatar.eda.event.UserCreatedEvent" project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserCreatedEvent.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="145" y="618"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="8" language="java" name="com.iluwatar.eda.event.UserUpdatedEvent" project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserUpdatedEvent.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="769" y="455"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="9" language="java" name="com.iluwatar.eda.event.Event" project="event-driven-architecture" 
+    file="/event-driven-architecture/src/main/java/com/iluwatar/eda/event/Event.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="299" y="460"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <dependency id="10">    
+    <bendpoint x="869" y="253"/>    
+    <end type="SOURCE" refId="2"/>    
+    <end type="TARGET" refId="8"/>  
+  </dependency>  
+  <dependency id="11">    
+    <bendpoint x="140" y="196"/>    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="9"/>  
+  </dependency>  
+  <dependency id="12">    
+    <bendpoint x="17" y="90"/>    
+    <bendpoint x="17" y="708"/>    
+    <bendpoint x="939" y="703"/>    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="1"/>  
+  </dependency>  
+  <dependency id="13">    
+    <bendpoint x="935" y="318"/>    
+    <bendpoint x="936" y="417"/>    
+    <end type="SOURCE" refId="2"/>    
+    <end type="TARGET" refId="1"/>  
+  </dependency>  
+  <dependency id="14">    
+    <bendpoint x="757" y="378"/>    
+    <end type="SOURCE" refId="2"/>    
+    <end type="TARGET" refId="9"/>  
+  </dependency>  
+  <generalization id="15">    
+    <end type="SOURCE" refId="7"/>    
+    <end type="TARGET" refId="9"/>  
+  </generalization>  
+  <association id="16">    
+    <end type="SOURCE" refId="8" navigable="false">      
+      <attribute id="17" name="user"/>      
+      <multiplicity id="18" minimum="0" maximum="1"/>    
+    </end>    
+    <end type="TARGET" refId="1" navigable="true"/>    
+    <display labels="true" multiplicity="true"/>  
+  </association>  
+  <realization id="19">    
+    <end type="SOURCE" refId="2"/>    
+    <end type="TARGET" refId="5"/>  
+  </realization>  
+  <dependency id="20">    
+    <end type="SOURCE" refId="5"/>    
+    <end type="TARGET" refId="9"/>  
+  </dependency>  
+  <dependency id="21">    
+    <bendpoint x="301" y="114"/>    
+    <end type="SOURCE" refId="5"/>    
+    <end type="TARGET" refId="4"/>  
+  </dependency>  
+  <realization id="22">    
+    <end type="SOURCE" refId="9"/>    
+    <end type="TARGET" refId="4"/>  
+  </realization>  
+  <dependency id="23">    
+    <end type="SOURCE" refId="6"/>    
+    <end type="TARGET" refId="9"/>  
+  </dependency>  
+  <generalization id="24">    
+    <end type="SOURCE" refId="8"/>    
+    <end type="TARGET" refId="9"/>  
+  </generalization>  
+  <dependency id="25">    
+    <bendpoint x="141" y="250"/>    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="7"/>  
+  </dependency>  
+  <association id="26">    
+    <end type="SOURCE" refId="6" navigable="false">      
+      <attribute id="27" name="handlers">        
+        <position height="19" width="56" x="449" y="175"/>      
+      </attribute>      
+      <multiplicity id="28" minimum="0" maximum="2147483647">        
+        <position height="17" width="23" x="574" y="173"/>      
+      </multiplicity>    
+    </end>    
+    <end type="TARGET" refId="5" navigable="true"/>    
+    <display labels="true" multiplicity="true"/>  
+  </association>  
+  <association id="29">    
+    <end type="SOURCE" refId="7" navigable="false">      
+      <attribute id="30" name="user"/>      
+      <multiplicity id="31" minimum="0" maximum="1"/>    
+    </end>    
+    <end type="TARGET" refId="1" navigable="true"/>    
+    <display labels="true" multiplicity="true"/>  
+  </association>  
+  <realization id="32">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="5"/>  
+  </realization>  
+  <classifier-display autosize="true" stereotype="true" package="true" initial-value="true" signature="true" 
+    sort-features="false" accessors="true" visibility="true">    
+    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
+    <operations public="true" package="true" protected="true" private="true" static="true"/>  
+  </classifier-display>  
+  <association-display labels="true" multiplicity="true"/>
+</class-diagram>
\ No newline at end of file
diff --git a/event-driven-architecture/index.md b/event-driven-architecture/index.md
index 40d84004d..6c2ae99c6 100644
--- a/event-driven-architecture/index.md
+++ b/event-driven-architecture/index.md
@@ -6,7 +6,7 @@ permalink: /patterns/event-driven-architecture
 
 **Intent:** Send and notify state changes of your objects to other applications using an Event-driven Architecture.
 
-![alt text](./etc/class_diagram.png "Event Driven Architecture")
+![alt text](./etc/eda.png "Event Driven Architecture")
 
 **Applicability:** Use an Event-driven architecture when