Same way the best engineers "prepare" for a job interview - by largely ignoring it. Instead of studying Java certification books they hack in Python, C, and Haskell and read about interesting algorithms in their spare time. When it's time for a job interview, all they have to do is show up.
If you talk to one of your target customers and one startup founder in a similar field a day, in three months you will have spoken to ~180 people that are intimately related to your business. You'll know more about your domain than you ever wanted to, and when the YC interview comes, there is nothing to prepare for.
If you talk to one of your target customers and one startup founder in a similar field a day, in three months you will have spoken to ~180 people that are intimately related to your business. You'll know more about your domain than you ever wanted to, and when the YC interview comes, there is nothing to prepare for.