Matrix damage is repaired by the Engineering skill rather than the Electronic skill.
Engineering have the following suggested specializations: Aeronautics Mechanic, Automotive Mechanic, Demolitions, Gunnery, Industrial Mechanic, Lockpicking, Nautical Mechanic
Electronics have the following suggested specializations: Computer, Hardware, Software
"Rigging" list Cracking, Electronics, Engineering and Perception as having important roles to play (besides Piloting which is the big one).
"Matrix" list Engineering as a useful skill to keep gear working properly (besides Cracking and Electronics which are kinda obvious).