It may be obvious that the massive credit card company Mastercard is heavily involved in big data. They have over 1.9 billion credit cards world wide that do over 65 billion transactions per year. They have over 32 million online and offline merchants that accept credit cards from Mastercard and 22.000 issuers and their credit cards are accepted in 210 countries. They use 700.000 rules to automatically clean, aggregate and augment their over 10 Petabytes of data. Apart from of course preventing fraudulent behaviour and identifying and preventing fraudulent transaction before they occur, Mastercard applies big data in another innovative way. It knows what everyone buys and they are using big data techniques to offer reports, insights, customer information and forecasts to their merchants.
Source: Datafloq https://datafloq.com/read/mastercard-applies-big-data-to-help-retailers-achi/320
How to be a Big Data Scientist 