Barclays is using MongoDB as an operational data store to extract and replicate data in near-realtime away from the mainframe. The bank has 6.5 million customers on its mobile apps, which log in at least once every 15 days. Barclays has plans to even let customers carry out some of their banking transactions on Facebook, under the new PSD2 EU directive. This has meant that Barclays can now provide better services, such as giving a full set of transaction history, as opposed to just the last 300 transactions that was possible before.”]
Source: https://diginomica.com/barclays-has-plans-to-let-customers-use-facebook-for-banking