Added basic async/await timings to prove how it works.

learning/dotnet/async-lab/Program.cs

@@ -0,0 +1,32 @@
+using System.Diagnostics;
+
+long startTime = Stopwatch.GetTimestamp();
+
+Console.WriteLine(
+    $"[Program] start - thread {Environment.CurrentManagedThreadId}, t = {Stopwatch.GetElapsedTime(startTime).TotalMilliseconds} ms"
+);
+
+var task = FetchUserAsync(42);
+Console.WriteLine(
+    $"[Program] after fetch - thread {Environment.CurrentManagedThreadId}, t = {Stopwatch.GetElapsedTime(startTime).TotalMilliseconds} ms"
+);
+
+var user = await task;
+Console.WriteLine(
+    $"[Program] after await - thread {Environment.CurrentManagedThreadId}, t = {Stopwatch.GetElapsedTime(startTime).TotalMilliseconds} ms"
+);
+
+return;
+
+async Task<string> FetchUserAsync(int id)
+{
+    Console.WriteLine(
+        $"[FetchUserAsync] entered - thread {Environment.CurrentManagedThreadId}, t = {Stopwatch.GetElapsedTime(startTime).TotalMilliseconds} ms"
+    );
+    await Task.Delay(500);
+    Console.WriteLine(
+        $"[FetchUserAsync] resumed, thread {Environment.CurrentManagedThreadId}, t = {Stopwatch.GetElapsedTime(startTime).TotalMilliseconds} ms"
+    );
+
+    return $"User ID: {id}";
+}

learning/dotnet/async-lab/async-lab.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0</TargetFramework>
+    <RootNamespace>async_lab</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>