definitely.ts

type Maybe<T> = T | null;

type BlogPost = {
  title: string;
  author: string;
}

type BlogPostResponse = Maybe<{
  title?: Maybe<string>,
  author?: Maybe<string>,
}>;
  
const myBlogPost: BlogPostResponse = {/*..*/};
myBlogPost?.title // Maybe<string> | undefined

//
// Type to unwrap the nested maybes into a concrete type
//

declare type Definitely<T> = NonNullable<{ [K in keyof T]-?: NonNullable<T[K]> }>;
  
const myBlogPost: Definitely<BlogPostResponse> = {/*..*/};
myBlogPost.title // string