This paper introduces NexOz, an approach and tool to facilitate incremental integration of AI components into interactive systems using a Wizard of Oz (WOz). The paper explores various challenges of AI integration, such as contextual understanding, conversational interaction, state tracking, and gesture recognition, particularly within the context of an operator support system in the manufacturing industry. NexOz allows developers to simulate AI functionalities through human intervention, enabling rapid prototyping, experimentation, and data collection. By leveraging a human wizard to emulate AI behavior in a structured way, NexOz facilitates the design and testing of dialogue flows, interaction patterns, tracking mechanisms, and conversational designs in real-time without having a fully-fledged implementation of AI-based solutions. Through iterative refinement and continuous feedback loops, NexOz offers a pragmatic approach to navigate the complexities of AI integration in interactive systems.