Gustaf Alströmer (00:00:00): If I drill down what makes companies fail, it's quite simple. It's just like they don't talk to users, which means they don't find product market fit. And if they don't find product market fit, nothing else really matters. What mistakes do people make is like it is all about that. It's all about talking to customers and learning that you're building something that's actually useful. YC Slack headline is make things people want, and it's still true and it's always going to be true. Lenny (00:00:30): Welcome to Lenny's Podcast where I interview world-class product leaders and growth experts to learn from their hard one experiences building and growing today's most successful products. Today my guest is Gustaf Alstromer. Gustaf is a group partner at Y Combinator where he's been for almost six years. Prior to that, Gustaf was at Airbnb for over four years where he started the original Airbnb growth team and where I was very lucky to get to work alongside him for a number of years. Gustaf is also at the heart of YC's increased focus on climate tech, and in my opinion is one of a handful of people who've had an incredible impact on the increasing amount of investment and people flowing into climate tech. (00:01:10): We chat in depth about what's happening in climate tech, why things have shifted so much recently, what's new and exciting, and how to think about the space if you're hoping to make the jump. We also get deep into Gustaf's experience working with over 600 startups over his time at YC. We talk about what are the most common mistakes that early stage startups and founders make, what advice YC partners give founders most often, the most common attributes of successful founders, the importance of having a technical co-founder and why that's the case, so much more. I guarantee you will leave this episode smarter and more inspired and I can't wait for you to hear it. With that, I bring you Gustaf Alstromer after a short word from our w...