I’ve worked with Worldline in a Rails project before and while it’s not as widely documented as Stripe or PayPal, it works well once set up correctly. If you're part of a blockchain development company or working with one, the best approach is to use their REST API and handle the payment flow from your backend. Make sure to securely store the API keys and use HTTPS for all transactions. You should also verify payment callbacks properly to avoid any issues with fake requests. If you are using Webhooks, set up background jobs to process them. Let me know if you need code examples and I can share how we handled the integration in our app.