Adyen is a Dutch payment company with the status of an acquiring bank. It lets businesses accept payments online, in apps and in person on one platform, through a single API. Besides processing, it offers risk management, local acquiring and embedded financial products such as business accounts, financing and card issuing. It is a hosted service and says it holds banking licences in the EU, the UK and the US.
Adyen is headquartered in Amsterdam and listed on Euronext Amsterdam. According to its infrastructure page, it runs its main systems in separate data centres in Europe and the US, and the French version of the page also lists Australia. All processed payments are stored in Europe, and Adyen states that it does not use public cloud services for payment processing. The platform is not open source. For a European organisation, the provider is a Dutch company under EU law, while processing also takes place outside Europe; check this in the data processing terms.