Product CTOs working with CIOs to add the internet-of-things (IoT) to their products quickly learn that doing so involves more than adding in sensors. They face four major challenges that unfold as they work through the design, production, and support journeys. For help, product CTOs can choose tech solutions vendors or professional services firms as their primary partners. This report outlines the different merits of each path and the typical strengths and weaknesses of 10 categories of vendors that product CTOs can choose from.