This paper presents an application called "Bank Management" for a banking institution. It is an offline application that requires installation on the host (server) and can be used in the absence of an Internet connection. Created applications of the same kind which exists on the market differ from this by several aspects: firstly uses a client-server architecture whose main advantage is that it can run multiple instances of the same application (run on different computers or on one computer at the same time),  secondly client-server is implemented using threads or wires so competitive access is allowed, competitive programming is used, not the classic sequential one, and not least, the application uses the highest level of abstraction in Java: Design Patterns, whose main advantages are that they are templates used to solve common programming problems, so they ensure code reusability and maintainability. Design Patterns used are: behavioral and Observer, Creational: Factory Method, or architecture: business logic sub-Transaction Script pattern.