[Chyzwar]

Building services for user facing applications. Banks have multi tiered architecture. They have back-end services (transactions, batch jobs, risk, calculations, analytics etc) these would be written in mostly in Java/Python/Scala/C#/C++. You might have situation where there is multiple systems processing same transactions overnight. Banks also have quite a lot of user facing applications, most of these now use React/Angular but data fed to it will not be coming from same services that process transactions(security and ease of maintenance). You will but another service just for frontend application that access back-end services via limited API or event queue.

Keep in mind that there is also plenty of systems that are older than me and have massive teams. Banks are mixed bag. You can work in amazing cutting edge project or maintain project in dead language.