Software invisible to the eye used to control, calculate and communicate is called Firmware. As an example, all functions of a Flatscreen TV Set are provided by its firmware.
The requirements for Firmware are quite different from those for software written for servers or PCs. In most cases, limited compute power and limited memory are to be found. Efficient programming under such limitations (that are intended due to ather constraints, like the limited available space, power limitations and so forth) requires long years of experience as well as indepth knowledge of the processor architectures used.
Our team of developers has decades of experience, a lot of which were gathered developing communication software and protocol stacks in telecommunications industry and other environments.