Although many open-source developer tools exist for building intelligent chatbot agents, these still have limitations with a few basic features and do not provide enough support for building commercialized products and low-resource languages like Vietnamese with a whole Natural Language Understanding (NLU) life-cycle. Thus, building an in-house system will be necessary for enterprises to have a unique competitive advantage. To fill this gap, we introduce CircleNLU as a Data-Driven NLU system with a range of features such as pseudo annotation, massive deployment, machine learning (ML) development process, and others. This paper shares our system architecture and sees how it works.