While you would be planning to have a payment processing system in place, you would be wondering about the Airbnb payment system, Airbnb payment process, Uber payment system etc. owing to the complexity involved. Although Airbnb founders claimed that they started with Braintree back in 2010-11 for their payment processing needs, they had to diversify and make use of multiple payment processors owing to the growth of their business to different countries.
Airbnb and Uber can be categorized under something known as online marketplaces. While they build a payment processing system, they will focus only on the functionality they require and accordingly develop a payment gateway. For an online marketplace model, entities such as payment facilitators, merchants and affiliates necessarily need to exist. Due to this, they will be able to have a good business logic and have well-defined framework to handle all their payment processes.
Ultimately, based on the model of marketplace and the functionality required, payment gateway and payment processing systems must be selected. If you wish to know more about online marketplace and payment processing systems, feel free to reach out to Open Source platform!