I had a chance to talk with the CTO of Nubank couple of years ago at DCD. They did exactly what you describe - Datomic was the tech choice, Clojure naturally followed from that. Can't tell for the rest :)
A lot of fintech is sending/receiving/transforming messages of varying tedious financial formats, which maps very nicely to Clojure's data-first ideology
3👍A follow-up to the recent discussion about whiteboard interviews: https://news.ncsu.edu/2020/07/tech-job-interviews-anxiety/
6👍