YC interviews are far better documented than I realized: https://hn.algolia.com/?query=yc%20interview&sort=byPopulari...

Firsthand experiences: http://initialized.com/last-minute-tips-for-yc-interviewees, https://hackernoon.com/how-to-ace-your-yc-interview-5c078aea..., https://alchemist.svbtle.com/our-yc-interviews

Simulators/questions: https://jamescun.github.io/iPG/, http://proto.dheera.net/yc/

Yah, I did one for S17, and they are the same as the in-person interview. This is usually a good sign coz it means they like you, but there's something in your application they need clarity on. Know your weaknesses, and be prepared to defend them with solid arguments. Good luck!

Are you based outside of the US? It sounds like most of the pre-interviews have been with teams in other countries.