Most early-stage founders get PMF wrong when fundraising, and that could kill their chances with YC and investors. Building a product people want is not enough, you have to prove demand with cold hard numbers. I’ve seen many founders say things like "strong engagement" or "viral growth" without being able to back that up, it only sows doubt instead of trust.
PMF isn’t a checkbox, it’s a grind. Investors expect you to show ongoing learning from data and market feedback. Startup journey is messy, rejection and mistakes are always part of the story, and hiding them just raises red flags.
Communicate clearly and honestly, don’t bluff. That’s how you build credibility. I’ve seen startups get into YC after multiple rejections simply because they were transparent and logical. Be real about where you are and where you’re going, or you won’t get far.