They say, “don’t judge a book by its cover”, and this apparently simple banking application has proved them right. Nowadays, people rarely build everything from scratch. Instead, they use third party libraries which make them sloppy at “real” coding. I built this banking application with nothing but C++ and IT WORKS. It is fully object oriented and it is just like any other automatic banking application that we see in ATMs or banks with inbuilt voice assistance. The main focus while building this app was not on the UI aspect, but on the underlying data structures and algorithms used to support this application. When the application loads, it fetches data from the system and stores it in a hybrid double hashed array of linked lists which reduces the time complexity of searching/inserting/deleting/updating user objects and this ADT can theoritically hold over a billion users. The double hashing is performed on the users’ auto generated account numbers and it is completely abstracted away from them.

This application has all the typical features of a bank, like opening an account, sending or receiving money, getting interest at a particular rate, account history checking, etc. etc. 

This application also has an admin access panel hidden in plain sight. Just like in movies, when you enter a particular combination of keys, you can unlock the admin access area from where you can log in and manage accounts of all your users.