type DeepPartial<T> = T extends object ? {
  [P in keyof T]?: DeepPartial<T[P]>;
} : T;

interface UserProfile {
  id: string;
  name: {
    first: string;
    last: string;
  };
  contact: {
    email: string;
    phone?: string;
  };
  tags: string[];
}

// Example Usage:
type PartialUserProfile = DeepPartial<UserProfile>;

const updatePayload: PartialUserProfile = {
  name: {
    first: "Jane" // 'last' is now optional
  },
  contact: {
    phone: "123-456-7890" // 'email' is now optional
  }
  // 'id' and 'tags' are also optional
};

const completePayload: UserProfile = {
    id: "123",
    name: { first: "John", last: "Doe" },
    contact: { email: "john@example.com" },
    tags: ["admin"]
};

const partialUpdate: DeepPartial<UserProfile> = {
    name: { first: "Johnny" }
};

// const invalidUpdate: DeepPartial<UserProfile> = {
//     name: { middle: "A" } // Error: 'middle' does not exist on type '{ first?: string | undefined; last?: string | undefined; }'
// };