diff --git a/Roadmap/23 - SINGLETON/swift/allbertoMD.swift b/Roadmap/23 - SINGLETON/swift/allbertoMD.swift
new file mode 100644
index 0000000000..7f255493f7
--- /dev/null
+++ b/Roadmap/23 - SINGLETON/swift/allbertoMD.swift	
@@ -0,0 +1,90 @@
+import Foundation
+
+
+
+class Singleton {
+    // Propiedad estática que contiene la única instancia de la clase
+    static let shared = Singleton()
+    
+    // Inicializador privado para prevenir la creación de otras instancias
+    private init() {}
+    
+    // Métodos y propiedades de la clase
+    func sayHi(to name: String) {
+        print("Hi, \(name)")
+    }
+}
+
+// Acceso global desde cualquier parte del código
+let instance1 = Singleton.shared
+instance1.sayHi(to: "Charly")
+
+let instance2 = Singleton.shared
+instance2.sayHi(to: "Marta")
+
+// Verificar que ambas referencias apuntan a la misma instancia
+print(instance1 === instance2)  // true
+
+
+
+
+// DIFICULTAD EXTRA
+print("\nDificultad Extra.\n")
+
+
+class UserSession {
+    static let shared = UserSession()
+    
+    private init() {}
+    
+    var id: String = ""
+    var userName: String = ""
+    var name: String = ""
+    var email: String = ""
+    
+    func assigntID(_ id: String) {
+        self.id = id
+    }
+    
+    func assigntUserName(_ userName: String) {
+        self.userName = userName
+    }
+    
+    func assigntName(_ name: String) {
+        self.name = name
+    }
+    
+    func assignEmail(_ email: String) {
+        self.email = email
+    }
+    
+    func showSessionInfo() {
+        print("id: \(id)")
+        print("User Name: \(userName)")
+        print("Name: \(name)")
+        print("email: \(email)")
+    }
+    
+    func removeSession() {
+        id = ""
+        userName = ""
+        name = ""
+        email = ""
+        print("\nSession Removed")
+    }
+}
+
+
+let userSession = UserSession.shared
+
+userSession.assigntID(UUID().uuidString)
+userSession.assigntUserName("Teophilus")
+userSession.assigntName("Pablo")
+userSession.assignEmail("tphls@gmail.com")
+
+userSession.showSessionInfo()
+userSession.removeSession()
+
+
+
+