This depends somewhat on whether the applicant is entry level or senior, but for a senior EE I'd look for
Accomplished - active in design, no dead wood
Organized - every EE has a process, if the process is messy so is the design
Humble - Arrogance begins when learning from ones mistakes ends. The majority of good EEs I've worked with have been humble
Deliberate - the flip of a switch can do a lot of damage
Reluctant to take shortcuts - in a complex design there are many temptations to cut corners.
Communicative - Willing and able to clearly argue for and teach their designs
Open - willing to consider addition of features, a different communication interface, higher performance, greater safety factor, lower cost etc. Some fall in love with their work and are genuinely annoyed at the idea of changing it.