Launch Club

Everything Moonshot's co-founders learnt from applying for Y Combinator

"I wasn’t expecting anything; I was sure we had a horrible application."

By
Daniel Han-Chen
August 15, 2025

‘Y Combinator? What’s that?'

That was my first reaction in September 2021 when my fellow founders in Startmate Founder’s Fellowship posted about applying to YC!

So I did some research, and OH MY, September 9 was the deadline for the Winter 2022 batch. It was already September 8, so I quickly cobbled up an application in the last remaining hours. I was sweating and my heart was pounding like crazy. I recorded a 1-minute intro, had no time for a demo, and submitted it at 4am Sydney time. (Luckily I’m a night owl!)

I wasn’t expecting anything; I was sure we had a horrible application. No demo. No co-founder (my brother was sleeping so didn’t want to wake him up).

Emailing YC won’t hurt, right?

On September 28, I decided to email YC, and ask them about adding my brother to our application. I was super anxious they wouldn’t reply, but literally a few hours later, they opened the application! We added a new 1-minute intro featuring my brother, and edited parts of our application that had co-founder impacts.

Emailing YC again?

On October 4, we made a 4-minute demo of Moonshot! I messaged YC, but got no response until…

YC reopened applications on October 7! We were shocked and elated! What did this mean? Can we edit any part of our application? We asked around, and it seemed like many people got the same email. We polished our application, and submitted it on October 10. 

At Moonshot, we’re making science fiction a reality. Our mission is to create a full world simulation to predict the future of everything. We’re predicting climate change, the weather, stock prices, fire, flood risks, air pollution, cancer rates, how long you’ll live and more!

My brother then made a new website, we had some investor chats courtesy of Startmate, and got into Blackbird Giants! We then emailed YC again.

Then…

WHAT!!! Rejections were supposed to be sent on November 19, so we were already preparing for the worst, but we secured an interview for December 2. I was shocked; I first thought the email was the rejection email!

Before the interview

I made small flash cards with my brother, and practised and practised and practised! Here are a few of the questions we tried answering.

  • ‘Why are you the right team to make it?’
  • ‘Why hasn’t somebody else done this before?’
  • ‘What’s your unique insight?’

The interview

The YC partners were super nice! They asked some tough questions on profit generation for our world simulation, but were more fascinated about our fast algorithms, which are used by Microsoft, NVIDIA and Facebook! They advised us to focus on selling our algorithms first, then building the world simulation.

Oh well!

Sadly, we did not make it in! We took the rejection email positively though. We’ll definitely refine our approach: focus first on generating profit with our fast algorithms and predictions for 6-12 months, and keep the world simulation as a longer term goal! 

I want to truly thank YC, since they woke us up, and made us first focus on revenue generation!

Lessons

  1. Maximise luck. It might sound cliche, but luck is important! Not luck luck, but probabilistic luck! If you have a 1% chance, you have to try 100 times for that one final person to say ‘yes’! We’ve chatted with multiple investors, tried applying to YC, and we’ve failed many times, but keep keep keep trying!
  1. Like-minded people matter. Without Startmate’s Founder’s Fellowship, we would have never known about YC, let alone be able to contact so many investors. The program also gave us preparation time — we made a website, logos, UI and UX designs and more.
  1. Never give up. Although we got rejected, we’re going to push on! After the interview, we posted our predictions for December inflation and what the Federal Reserve will do. I did not expect so many comments on our Reddit post!

Daniel Han-Chen
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