I'd argue as a hobbyist you can get away with "block level" design - understand enough to know what you need, read datasheets and implement a reference design. For example making a stepper motor do what you want - probably not, just buy a driver board and look at example code and a reference circuit. Same goes for a high power motor: either you buy a pre-made board that has the right spec, or you look up a reference circuit with a common control IC. Most digital design can be done in this way; you need to know how to program as well.
Analog is in some ways more complicated. But there are lots of reference designs for blocks like filters and amplifiers and you can look at the pros/cons of different circuits. A good companion to this sort of design work is Horowitz and Hill. Even high frequency board design can mostly be achieved around by following best practices unless you're doing stripline RF stuff.
The difference lies in things like designing extremely efficient circuits (optimize for part number, cost, etc) and designing boards that can be certified. You can get away with a lot if you're not designing to a tight spec.
Analog is in some ways more complicated. But there are lots of reference designs for blocks like filters and amplifiers and you can look at the pros/cons of different circuits. A good companion to this sort of design work is Horowitz and Hill. Even high frequency board design can mostly be achieved around by following best practices unless you're doing stripline RF stuff.
The difference lies in things like designing extremely efficient circuits (optimize for part number, cost, etc) and designing boards that can be certified. You can get away with a lot if you're not designing to a tight spec.