Service-oriented architectures are more popular than ever, and increasingly companies and organizations depend on services offered through Web APIs. The capabilities and complexity of Web APIs differ from service to service, and therefore the impact of API errors varies. API problem cases related to Adyen's payment service were found to have direct considerable impact on API consumer applications. With more than 60,000 daily API errors, the potential impact is enormous. In an effort to reduce the impact of API related problems, we analyze 2.43 million API error responses to identify the underlying faults. We quantify the occurrence of faults in terms of the frequency and impacted API consumers. We also challenge our quantitative results by means of a survey with 40 API consumers. Our results show that 1) faults in API integration can be grouped into 11 general causes: invalid user input, missing user input, expired request data, invalid request data, missing request data, insufficient permissions, double processing, configuration, missing server data, internal and third party, 2) most faults can be attributed to the invalid or missing request data, and most API consumers seem to be impacted by faults caused by invalid request data and third party integration; and 3) insufficient guidance on certain aspects of the integration and on how to recover from errors is an important challenge to developers.@en

The payment industry has been characterized by a small number of players that operate the schemes for the facilitation of credit and debit card payments. Over the years, various initiatives have been taken in order to increase competition and hence cost efficiency within the industry. One of the latest efforts is the introduction of Payment Service Directive II (PSDII) within the European Union. PSDII requires banks to open up their services to Third Party Payment (TPP) networks. TPP networks make use of banks’ payment initiation services for e-commerce transactions, creating an alternative next to credit and debit card payments. However, just like in the card networks, payment fraud is not absent in TPP networks. Fraud manifests itself in non-payments: authorized payments that do not get settled. In this paper we first analyze the ecosystem dynamics of the TPP network by examining the role of each actor involved. By leveraging one year of transaction data from the TPP network, we estimate the prevalence of non-payments. Finally, we evaluate a preventive and reactive risk management strategy. The latter strategy comprises of a non-payment recovery process — sending the consumer a reminder of the due amount—and proves to be surprisingly effective. Additionally, we have evidence that combining both strategies into a continuous risk management process can yield even better results. As non-payment in the TPP network has similarities with chargebacks in the card network, we believe that our approach can also enhance risk management in the card network. @en