Create AI Engine

I am looking for a freelancer to help me create an AI Engine. Specifically, I am interested in creating a Natural Language Processing engine that can be used to develop a Chatbot. I have a specific use case in mind and I need someone with experience in developing Chatbots to help me create this engine. I have a preference for using a ASP.NET language. The ideal candidate for this job should have experience in developing NLP engines and Chatbots