diff --git a/interface/.vscode/launch.json b/interface/.vscode/launch.json
new file mode 100644
index 00000000..003bd295
--- /dev/null
+++ b/interface/.vscode/launch.json
@@ -0,0 +1,26 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": ".NET Core Launch (console)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            "program": "${workspaceFolder}/bin/Debug/netcoreapp2.2/interface.dll",
+            "args": [],
+            "cwd": "${workspaceFolder}",
+            "console": "integratedTerminal",
+            "stopAtEntry": false,
+            "internalConsoleOptions": "openOnSessionStart"
+        },
+        {
+            "name": ".NET Core Attach",
+            "type": "coreclr",
+            "request": "attach",
+            "processId": "${command:pickProcess}"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/interface/.vscode/tasks.json b/interface/.vscode/tasks.json
new file mode 100644
index 00000000..5588cc6c
--- /dev/null
+++ b/interface/.vscode/tasks.json
@@ -0,0 +1,15 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "build",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "build",
+                "${workspaceFolder}/interface.csproj"
+            ],
+            "problemMatcher": "$msCompile"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/interface/Program.cs b/interface/Program.cs
new file mode 100644
index 00000000..209647ed
--- /dev/null
+++ b/interface/Program.cs
@@ -0,0 +1,126 @@
+using System;
+using System.Collections.Generic;
+
+/// <summary>
+/// Using an interface called IActivity a.k.a contract so that we can use it as a type instead of a concrete class type
+/// </summary>
+public class Program
+{
+    // Fields
+    static Engine _engine;
+    static Workflow _workflow;
+
+    // Properties
+    // n/a
+
+    // Constructor(s)
+    static Program()
+    {
+        _engine = new Engine();
+        _workflow = new Workflow();
+    }
+
+    // Methods
+    public static void Main()
+    {
+        _engine.Run(_workflow);
+    }
+}
+
+public class Engine
+{
+    // Fields
+    // n/a
+
+    // Properties
+    // n/a
+
+    // Constructor(s)
+    public Engine()
+    {
+        // not used
+    }
+
+    // Methods
+    public void Run(Workflow workflow)
+    {
+        foreach (var activity in workflow.GetActivities())
+        {
+            activity.Execute();
+        }
+    }
+}
+
+public class Workflow
+{
+    // Fields
+    List<IActivity> _activities;
+
+    // Properties
+    // n/a
+
+    // Constructor
+    public Workflow()
+    {
+        _activities = new List<IActivity>
+        {
+            { new SportActivity{Message = "Running..." } },
+            { new SportActivity{Message = "Batting..." } },
+            { new SportActivity{Message = "Kicking..." } },
+            { new SportActivity{Message = "Dribbling..." } },
+            { new OutdoorActivity{Message = "Fishing..." } },
+            { new OutdoorActivity{Message = "Camping..." } },
+            { new OutdoorActivity{Message = "Grilling..." } },
+            { new IndoorActivity{Message = "Gaming..." } },
+            { new IndoorActivity{Message = "Coding.." } },
+            { new IndoorActivity{Message = "knitting..." } },
+        };
+    }
+
+    // Methods
+    public List<IActivity> GetActivities()
+    {
+        return _activities;
+    }
+}
+public class IndoorActivity : Activity
+{
+    public override void Execute()
+    {
+        Console.WriteLine("Performing Indoor Activity: {0}", Message);
+    }
+}
+
+public class SportActivity : Activity
+{
+    public override void Execute()
+    {
+        Console.WriteLine("Performing Sport Activity: {0}", Message);
+    }
+}
+
+public class OutdoorActivity : Activity
+{
+    public override void Execute()
+    {
+        Console.WriteLine("Performing Outdoor Activity: {0}", Message);
+    }
+}
+
+
+//Here is an example of an interface
+public interface IActivity
+{
+    // Properties
+    string Message { get; set; }
+
+    // Methods
+    void Execute();
+}
+
+public abstract class Activity : IActivity
+{
+    public string Message { get; set; }
+
+    public abstract void Execute();
+}
\ No newline at end of file
diff --git a/interface/interface.csproj b/interface/interface.csproj
new file mode 100644
index 00000000..21dff5ca
--- /dev/null
+++ b/interface/interface.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp2.2</TargetFramework>
+  </PropertyGroup>
+
+</Project>
diff --git a/whiteboard20th/.vscode/launch.json b/whiteboard20th/.vscode/launch.json
new file mode 100644
index 00000000..a2796bee
--- /dev/null
+++ b/whiteboard20th/.vscode/launch.json
@@ -0,0 +1,26 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": ".NET Core Launch (console)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            "program": "${workspaceFolder}/bin/Debug/netcoreapp2.2/whiteboard20th.dll",
+            "args": [],
+            "cwd": "${workspaceFolder}",
+            "console": "integratedTerminal",
+            "stopAtEntry": false,
+            "internalConsoleOptions": "openOnSessionStart"
+        },
+        {
+            "name": ".NET Core Attach",
+            "type": "coreclr",
+            "request": "attach",
+            "processId": "${command:pickProcess}"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/whiteboard20th/.vscode/tasks.json b/whiteboard20th/.vscode/tasks.json
new file mode 100644
index 00000000..65b474fa
--- /dev/null
+++ b/whiteboard20th/.vscode/tasks.json
@@ -0,0 +1,15 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "build",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "build",
+                "${workspaceFolder}/whiteboard20th.csproj"
+            ],
+            "problemMatcher": "$msCompile"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/whiteboard20th/Program.cs b/whiteboard20th/Program.cs
new file mode 100644
index 00000000..fa5a3422
--- /dev/null
+++ b/whiteboard20th/Program.cs
@@ -0,0 +1,37 @@
+using System;
+using System.Collections.Generic;
+
+
+namespace whiteboard20th
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            string input = "";
+            while (input == "")
+            {
+                input = Console.ReadLine();
+            }
+            Console.WriteLine(UniqueChar.IsUnique(input) ? "All letters are unique" : "there are duplicate letters in that string");
+        }
+    }
+    public class UniqueChar
+    {
+        public static bool IsUnique(string word)
+        {
+            bool returnMe;
+            foreach (var letter in word)
+            {
+                char temp = letter;
+                bool result = false;
+                foreach (var item in word)
+                {
+                    result = temp == item ? true : false;
+                }
+                if (result) { returnMe = true; }
+            }
+            return returnMe;
+        }
+    }
+}
diff --git a/whiteboard20th/whiteboard20th.csproj b/whiteboard20th/whiteboard20th.csproj
new file mode 100644
index 00000000..21dff5ca
--- /dev/null
+++ b/whiteboard20th/whiteboard20th.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp2.2</TargetFramework>
+  </PropertyGroup>
+
+</Project>