Developing applications for the IoT requires knowledge and skills in many areas, from hardware design and network design to low-level and high-level programming languages.
Even if an IoT Engineer is focused on developing a part of the system (it can be connected devices, the networks over which they interact, IoT platforms or applications for end-users), they need to understand the principles of each part as well as the whole concept.Very few vacancies are posted in the domain of the Internet of Things . But it's not because no one needs IoT engineers. It's just that companies usually search for them with the help of recruitment agencies.
Since the IoT domain is new and complex, an Engineer has to take on some tasks that a Project Manager usually performs. This may include discussing solutions with the customer, preparing documentation, forming a team, and participating in the search and selection of contractors for the project.
For the IIoT (Industrial Internet of Things), experience with SCADA systems and industrial controllers (IEC 61131-3) would be a plus.