The way I see it is that the team was working on the payment system. She may well have specialized on some scaling aspects but that does not preclude her working within a team having responsibility for building or maintaining the payment system. Considering that Uber has a micro services architecture the teams will be organized vertically along end-to-end functionality and not along the architectural layers. In that way the story is consistent with what is publicly known about Uber IT.
That detail seems suspect to me. There are also essentially no details about the work that convey inside knowledge about the ideosyncracies of Uber specifically at a work place. It is also weird to me that she chose to be anonymous but included her height and a bunch of specific incidental details - it reminds me of how liars frequently add an excessive amount of detail to add credibility to their stories.
Personally it sounds true to me. but I'd like to see more scrutiny from someone with perspective on this.