I used to think each platform just built their own system, but it turns out many rely on full B2B solutions that handle things like player accounts, payments, and analytics all in one place. While looking into it, I found this article
visitstafford.org/soft2bet-overview-of-b2b-platforms-for-the-igaming-industry/ that explains how companies like Soft2Bet provide that kind of infrastructure. It actually makes sense — instead of building everything from scratch, operators can focus more on growth and user experience.