I'd recommend this HN post [0] which links to a good background story [1]. It literally starts with "For those who just came back from a 15 year space mission: Wirecard is a German company that..." haha.

[0] https://news.ycombinator.com/item?id=23598824

[1] https://valueandopportunity.com/2020/06/19/wirecard-the-germ...