Hi sir I see you are looking for someone to program a vending machine. I have experience in .programming c, c++, html, css and python. I am a robotic engineer and I work for robotics company and I did some IOT for some companies before just give me the full details and I will program your task with the best quality. This is not my personal account we can contact more and I can send you some of my IOT project that I have done before. I'll be glad to be on this project.