> However, this typecasting sometimes relied on what contemporary readers know to be harmful stereotypes. She frequently caricatured particular occupations and ethnic groups for comic effect, reinforcing the prejudices of her time.

I feel like, especially given that she was writing a century ago, Christie is relatively ahead of her time on this front.

For example, it's not uncommon that there will be a non-protagonist character who is like "Well of course the Italian did it, they love stabbing people!" or whatever stereotype of the time but that person is pretty much always wrong. It's pretty much never servants or random underclass people committing the murders either.