One challenge I have encountered while using Node-RED in an IoT project is the lack of support for some of the newer technologies. For example, I was working on a project that required me to connect an IoT device to a cloud platform, and while Node-RED had nodes to support the connection, it did not have any nodes to support the newer technologies that the cloud platform was using. This meant that I had to find an alternate way to connect the device to the cloud platform, which was time consuming and difficult.