Pros
Long interview process but it was worth it. Working with professionals, good friendly atmosphere. Focus on doing things the right way, instead of pushing artificial inflated deadlines. No micromanagement. Decent documentation for onboarding new people (which is important because this is not your typical backend API project). Great company potential with a long-term growth prospect.
Cons
The aforementioned growth could be faster but banking industry is not really known for it's agility, so it kinda comes with the territory. So for someone who likes high-paced dynamic environment this might not be the right place. On the flip side, when it comes to building the necessary infrastructure that will power instant transactions for the majority of the world, you might want to take your pace and do it good instead of fast.