This study presents lessons learned based on practical experiences of connecting devices to internet-of-things platforms in the context of research and academic coursework. The experiences are gathered from six research projects, one undergraduate course, and a few undergraduate theses over a three-year period. The lessons learned include: the trade-off of rapid prototyping over security is very common, example source code is not up to production standards, adherence to standards speeds development, debugging support for IoT systems is lacking, open source licenses varies, poor platform interoperability, and the array of service fees among platform providers obstruct cost comparisons.