Two-sided marketplace payments are complex because you're essentially operating as a payment facilitator. You need to handle seller onboarding with proper KYC verification, manage funds flow between parties, handle disputes and chargebacks, and ensure compliance with money transmission regulations in each jurisdiction you operate. Unless you have significant resources and regulatory expertise, I wouldn't recommend building this entirely in-house. The compliance burden alone is substantial. Look for platforms that offer split payment functionality, escrow services, and automated seller verification. Make sure they handle the regulatory heavy lifting while giving you flexibility to customize the user experience.