I've done both - I have a background in EE, verging on CompE. I've only ever done hardware professionally, however. I think my view of a prototype is more in l

I've done both - I have a background in EE, verging on CompE. I've only ever done hardware professionally, however. I think my view of a prototype is more in line with what an industry would view as a proof of concept - enough hardware to show that your vision is possible. I wouldn't want to show anything I built over a weekend to a VC in an effort to get them to fund me, unless I absolutely had to.