Type name repeated on both sides. Redundant.
// ❌ Verbose
Dictionary<string, List> dict = new Dictionary<string, List>();
// ✅ Target-typed new (C# 9+)
Dictionary<string, List> dict = new();
// Works everywhere
List users = new();
var service = new UserService();
return new User { Name = "John" };
// Field initialization
private readonly HttpClient _client = new();
When NOT to use: When type isn’t obvious from left side (use var instead).