In this episode of PMFers, we sit down with Paul Berg—founder of Sablier and creator of PRBMath—to explore his journey from teenage Objective-C freelancer to shipping one of the most widely used token streaming protocols on Ethereum. Paul shares how building Sablier in a bear market helped him learn the art of launching fast, getting feedback on crypto Twitter, and evolving from general-purpose primitives to use case–driven products like onchain payroll and vesting.

We dig into Paul’s love of type safety, his obsession with building great products, and how AI is becoming his junior dev (but not vibe coder). We also talk about the Ethereum accelerator debate, cross-border coordination games, rapamycin, sunk cost fallacies, and why building onchain is still open to the obsessed—even if you’re just starting out.

Whether you’re designing smart contracts, struggling to find users, or wondering what you actually need a blockchain for, this episode is packed with insight from someone who’s been there.