In this context, PE is the professional engineering exam. You take it in a specialty area, and software engineering was added last year. It's one of the last steps for licensure as a professional engineer.
Some states, like Texas, are extremely picky about who calls themselves an engineer, irrespective of industrial exemption (which the vast majority of people fall under). PE licensure in other engineering areas (like civil engineering) is required to offer services to the public, helps when offering expert testimony, and can be required for principals at consulting firms. The software engineering PE is an extension of IEEE's efforts in software engineering, and is probably a good thing for safety-critical industries.
Since passing the fundamentals of engineering (FE) exam is (usually) a prerequisite, someone who has a PE in software engineering probably knows their way around a free body diagram or Laplace transforms or MSD systems, i.e., stuff the other engineering fields do.
While I take the point that there is a difference between code-monkeys who don't have deep understanding and serious well grounded engineers, I don't agree that a two year old exam in a field that's had a history of failed certification attempts is a reasonable benchmark.
I think part of the problem in the field that contributes to the article is that the field is young and we don't have strong, well accepted professional organizations and licensure yet. We're still figuring out what those look like, and dealing with some serious challenges in breadth as we do so.
Engineering as a profession has a licensing system similar to medicine and law. In the US this involves several years of on the job training as a Jr Engineer and then passing two exams: the generic FE (Fundamentals of Engineering) and then a field specific PE (Principles and Practice of Engineering). Passing these exams and becoming licensed is all but required to practice civil engineering, but much less important in most other fields.
The "software engineering" PE is apparently pretty new (first offered in 2013) and kind of an oddball since this industry didn't grow out of any engineering tradition and doesn't really place too much value on certification.
Some states, like Texas, are extremely picky about who calls themselves an engineer, irrespective of industrial exemption (which the vast majority of people fall under). PE licensure in other engineering areas (like civil engineering) is required to offer services to the public, helps when offering expert testimony, and can be required for principals at consulting firms. The software engineering PE is an extension of IEEE's efforts in software engineering, and is probably a good thing for safety-critical industries.
Since passing the fundamentals of engineering (FE) exam is (usually) a prerequisite, someone who has a PE in software engineering probably knows their way around a free body diagram or Laplace transforms or MSD systems, i.e., stuff the other engineering fields do.