A/B testing is the experiment strategy, which is often used on web or mobile application development. In A/B testing, a developer has to implement multiple variations of application, assign each variation to a subset of the entire user population randomly, and analyze log data to decide which variation should be used as a final product. Therefore, it is challenging to keep the application code clean in A/B testing, because defining variations of software or assigning user to each variation needs the modification of code. In fact there are some existing tools to approach this problem. Considering such a context of A/B testing research, we propose the solution based on the interface Archface-U and AOP (Aspect Oriented Programming) which aims to minimize the complication of code in A/B testing.