For more than twenty years, applications based on P2P logic deliver more freedom to their users. From file-sharing to cryptocurrencies, they have revolutionized the way we design distributed systems, at a technical level and beyond. We believe that now is the time for a new wave of P2P systems: decentralized marketplaces. Relying on blockchains, they enable anyone to exchange services and monetize resources with no reliance on a trusted third party. Gilles will share the lessons learned at iExec with respect to the challenges faced when designing and deploying such a decentralized marketplace.