As the number of devices and platforms gradually increased that serve as a medium for online banking services, the number of replicated services for different platforms also increase. Each service has a different representation in a different platform even though targeting the same business objectives. This situation results in the problem of re-developing similar set of requirements for different devices and services which in turn results in multiplied effort in software development and degradation in the software quality because of the replicated code. The objective of this paper is to present a device independent user interface development approach that eliminates the replicated user interface development effort of the same set of services for different platforms/devices while increasing the presentation performance. In this context, we provide a basic technique that uses a json based user interface definition format, called omni-script, to separate the representation of banking services in different platforms/devices, so called channels. Omni-script is a pioneering solution being used in a real development environment in banking software domain that is experiencing a shift towards omni-channel user experience, where users are able to seamlessly continue using banking services in different platforms and devices. As the evaluation method, we have measured the actual development effort on a representative sample development team and a set of services. Additionally, we later deployed and measured the rendering time and the amount of data communication for the proposed approach in a real production environment. Production deployment resulted in a remarkable decrease in data communication and in loading times at the client side. As importantly, the proposed approach also resulted in a nearly 75% decrease in service development time by enabling analysts to produce user interface prototypes that can be integrated to service development with minimal effort.