As power-hungry tech companies work to fuel AI data centers, the race for nuclear energy is on. Amazon led a $500 million investment into X-Energy, which develops small modular reactors. We spoke with CEO Clay Sell on what’s behind the nuclear craze. Plus, AI startup Sierra just raised a new $175 million in capital, quadrupling its valuation from January to $4.5 billion. We sit down with co-founder Bret Taylor on the age of the AI agents.