Nextdoor CEO Nirav Tolia on bowling alone, AI bots, and why the heartland is happier than the coasts

Marco Zappacosta is the co-founder and CEO of Thumbtack, the home services marketplace he started in 2008. Thumbtack connects homeowners to 300,000+ local service professionals, with nearly 100M projects started on the platform. In this episode of Summation, Marco and Auren discuss:Why home services is bigger than groceries but barely any is booked onlineHow AI collapsed Thumbtack's product pod sizesWhy Silicon Valley underrates leadership and overrates management The single trait to screen every executive hire forYou can find Auren Hoffman on X at @auren and Marco Zappacosta on X at @mlz

Eric Ries created the Lean Startup methodology and authored the bestselling book of the same name, which has sold over a million copies. He's also the founder and executive chairman of the Long-Term Stock Exchange, the co-founder of Answer AI (an AI R&D lab), and the author of the upcoming book Incorruptible, releasing May 26th.In this episode of Summation, Eric and Auren discuss:why "bad governance" companies have outperformed "good governance" since 2008financial gravity - the invisible force that bends companies away from their missionthe foundation-controlled blueprint behind Novo Nordisk, IKEA, and Zeisswhy vibe coding is headed for its Chernobyl momentYou can find Auren Hoffman on X at @auren and Eric Ries on X at @ericries

Karl-Theodor zu Guttenberg became Germany's youngest Minister of Defense in history, and previously served as Minister of Economics and Technology. He is the chairman and founder of Spitzberg Partners, an investment and advisory firm, a bestselling author, and co-founder of Open Minds Media, where he produces films and podcasts. He co-hosts one of Germany's most popular podcasts.In this episode of Summation, KT and Auren discuss:Why Germany's defense spending hovered at 1% of GDP for decades and what finally forced a changeThe nuclear exit decision that was driven by a single state election and backfired spectacularlyHow Rheinmetall surpassed Volkswagen in market cap and what it signals about Europe's industrial reorientationWhy Germany's total stock market cap is less than a single US company like NvidiaYou can find Auren Hoffman on X at @auren and Karl-Theodor zu Guttenberg on Linkedin. 

Pat Gelsinger is the former CEO of Intel and longtime Silicon Valley leader.  He joins Auren to unpack the forces reshaping technology, geopolitics and leadership.After more than 30 years at Intel (including serving as its first CTO) and nearly a decade as CEO of VMware, Pat now sits at the intersection of deep tech and purpose-driven innovation as executive chair and head of technology at Gloo and general partner at Playground Global.In this episode of Summation, Pat and Auren discuss:Why the US now imports more from Taiwan than from China -- and what that means for national securityThe case for a U.S. sovereign wealth fund to counter China’s tech investments in semiconductors, energy, and rare earth mineralsWhat happened when Intel gave $70B back to shareholders instead of building fabs, and why tech companies need technologist CEOsAndy Grove's 35-year mentoring relationship with Pat, starting with a cold call that changed his careerYou can find Auren Hoffman on X at @auren and Pat Gelsinger on X at @PGelsinger

Vlad Tenev (Robinhood co-founder/CEO) and Tudor Achim (former helm.ai CTO) are the founders of Harmonic, an AI lab pioneering the path toward mathematical superintelligence. Together, they developed Aristotle, a model that eliminates hallucinations by reasoning in Lean code rather than natural language. By shifting from probabilistic guesses to formal logic, Aristotle produces 100% verified mathematical outputs. The model recently demonstrated its breakthrough capabilities by achieving gold-medal performance at the International Math Olympiad. In this episode of Summation, Vlad, Tudor, and Auren discuss:Why AI models struggled at math for so long How Aristotle helped 10x the total corpus of formally verified Erdos problems in just a few months Why formal verification will make all software dramatically saferHow the first Millennium Prize problem will be solved by 2027-2028You can find Auren Hoffman on X at @auren, Vlad Tenev on X at @vladtenev, and Tudor Achim on X at @tachim

John Allen is a retired four-star Marine Corps general who commanded 150,000 US and NATO troops in Afghanistan and built a 65-nation coalition as Special Presidential Envoy to the Global Coalition Against ISIS. After retiring from the military, he led the Brookings Institution as its president. He co-invented the term "hyperwar," holds five AI patents, and co-authored Turning Point: Policymaking in the Era of Artificial Intelligence. He currently serves as a strategic advisor to Microsoft.In this episode of Summation, John and Auren discuss:Why Ukraine's battlefield is accelerating the autonomous weapons timeline faster than any defense department predictedThe single assumption that doomed Afghanistan and why 2,500 troops could have changed everythingWhat nobody is asking about the US operation in Iran How China's one-child military could be the most underappreciated deterrent against a Taiwan invasionYou can find Auren Hoffman on X at @auren and John R. Allen on LinkedIn

Adrian Aoun helped found Torch, a health data platform that was acquired by OpenAI earlier this year. He's also the co-founder of Seneca, which raised $60 million to build autonomous drones for wildfire suppression. Adrian previously founded Forward Health. He previously led special projects for Larry Page at Google, where he founded Sidewalk Labs and helped build Google's AI division.In this episode of Summation, Adrian and Auren discuss:Why curing all cancer adds only ~3 years of life but internet access for a billion people is massively more impactfulHow AI is turning healthcare from a service into a product -- and why the AMA is the new taxi medallion lobbyThe expert investor paradox: why deep expertise makes you a worse angel investorWhy GLP-1s are the closest thing to a miracle drug in our lifetimeYou can find Auren Hoffman on X at @auren and Adrian Aoun on X at @adrianaoun

Tod Sacerdoti is the CEO and co-founder of Pipedream, which recently sold to Workday. Tod is also a general partner at Flex Capital, where he's invested in over 400 companies including Chime, Vercel, Replit, CodeRabbit, Mercury, and many others. He previously founded BrightRoll, a programmatic video advertising platform that sold to Yahoo for $640 million in 2014. In this episode of Summation, Tod and Auren discuss:Why seed investing has the highest annualized returns of any venture asset classFirst-gen AI companies being the most vulnerable to AI disruptionQSBS and why it's the most important tax benefit nobody talks aboutThe founder code and what happens when people break itYou can find Auren Hoffman on X at @auren and Tod Sacerdoti on X at @tod

Nirav Tolia is the co-founder and CEO of Nextdoor (NYSE: NXDR), the neighborhood social network with over 105 million users across 350,000 communities worldwide. After stepping down as CEO in 2018, he returned to lead the company in 2024.In this episode of Summation, Nirav and Auren discuss:Why success kills innovationThe death of physical communityWhy Nextdoor had to change their stock tickerInsider vs Outsider entrepreneursYou can find Auren Hoffman on X at @auren and Nirav Tolia on X at @niravtolia.

Lieutenant General Mike Fenzel recently retired as a three-star Army General. He most recently served as the United States Security Coordinator for Israel and the Palestinian Authority, navigating one of the world’s most complex geopolitical landscapes. His career is defined by high-stakes leadership, ranging from the immediate aftermath of the September 11th attacks, where he was stationed in the bunker alongside Vice President Dick Cheney, to multiple deployments to Afghanistan, to commanding an airborne brigade of 5,500 paratroopers. Beyond the battlefield, Fenzel is a scholar of strategic decision-making. His book, No Miracles, analyzes the internal Soviet failures during their occupation of Afghanistan.In this episode of Summation, Mike and Auren discuss:Why the Soviets took four years to exit AfghanistanLessons from leading security cooperation in JerusalemIsrael's dominance in security techWhy US foreign policy experts keep failingYou can find Auren Hoffman on X at @auren and Mike Fenzel on LinkedIn.