It can be, if what she knows is the company's own firmware, logic and calibration methods built on that platform, rather than the platform itself. The test is special knowledge of the petitioner's products or advanced knowledge of its processes, not general industry skill; the knowledge need not be proprietary, unique or narrowly held throughout the company.
The platform is general; the company's logic on it is not
Hypothetical example: a Haldimand County conveyor manufacturer employs a controls designer who works in a common PLC environment used across the industry, but the fault-recovery sequences, motor-load curves for the company's elevator legs and the dust-hazard interlocks are all written in-house and revised by her. USCIS distinguishes between skills widely available and knowledge of the petitioner's particular product or process. The claim should not be that she is an excellent programmer; it should be that the company's equipment cannot be commissioned or diagnosed without knowledge of code and design decisions that exist only inside the company, that she authored or maintains much of it, and that training a U.S.
hire to the same level would take an extended period. Support that with the number of engineers who share the knowledge, the training curriculum she runs, and examples of field failures only she resolved. The narrower and more documented the definition, the stronger the case.