I have been working in cross border payments since 2010 at my previous employer where we were processing millions per day from many countries around Asia Pacific region (Singapore to be specific). This was very exciting as it gave us exposure into global payment ecosystem but also challenged our team by introducing new methods/tools for risk management etc which had never seen before! We used different tools like Braintree API gateway or Xendesk integration toolkit - all paid products not free ones offered under open source community.