Disgruntled former Monzo customer here. Do they still have a haywire fraud detection system that randomly freezes innocent people's accounts? It's happened to countless users and the customer experience when they do it ("we refuse to tell you why" and in some cases holding onto their money for months) is a kafkaesque nightmare.
https://www.vice.com/en/article/bvg7n3/monzo-freezing-closin...
https://www.reddit.com/r/UKPersonalFinance/comments/db9j5z/m...
https://www.theguardian.com/money/2020/jun/06/monzo-customer...
I'd be far more interested in a blog post explaining that than how great their infrastructure is.