This makes sense to me as someone educated as an electronics engineer. I've since moved over to software development and on occasion feel it can be called engineering, but more often it cannot.

> building something according to formal specifications within constraints...

Yes this is close to what I consider engineering, but maybe it is better to say 'design something according formal specifications within a set of constraints'. Engineering is a process of design. Does this mean implementation is excluded from the definition of engineering?

Plumbers and carpenters build according to specifications and architects design the specifications yet neither are called engineers.

Software development more often than not has little in terms of formal specifications and design, and as the article points out it is very much a field of change. It also focuses mostly on implementation instead of design. That is closer to what a plumber, carpenter and other tradesmen do.