Well, "engineer" means real maths/physics/chemistry applied to information systems. If not, it is "technician" (well, in my country). Most "engineers" actually work at a "technician" level.
Where a systems technician may get in trouble: accurate and proven floating point calculations and where it comes from (minimal polynomial, range reduction, etc), real understanding of the maths of cryptography. Proofs of common performant algorithms (ring buffers synchronized with atomic variables, unification,etc).
It may need a deep understanding of signal processing, depending on the field, etc etc.
But since everything was already put in boxes (libs), a systems technician can re-use mostly all of them: the set of skills required is no higher than high school level.
Basically, an engineer has a deeper undertanding of information systems, but work most of the time as a "technician", and has some background knowledge to help him/her ramp up on tricky stuff.
Where a systems technician may get in trouble: accurate and proven floating point calculations and where it comes from (minimal polynomial, range reduction, etc), real understanding of the maths of cryptography. Proofs of common performant algorithms (ring buffers synchronized with atomic variables, unification,etc). It may need a deep understanding of signal processing, depending on the field, etc etc.
But since everything was already put in boxes (libs), a systems technician can re-use mostly all of them: the set of skills required is no higher than high school level.
Basically, an engineer has a deeper undertanding of information systems, but work most of the time as a "technician", and has some background knowledge to help him/her ramp up on tricky stuff.