system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Was C-3PO a kit or already partially assembled or something or did Anakin really assemble a fully-functioning artificial intelligence out of spare parts?
gpt
Anakin built him out of spare parts, but one of those spare parts was a functional droid brain.  Also 3P0 units were an existing line of droids.  

So basically Anakin was showing some good skill as a mechanic, but not necessarily programming or engineering.  He didn't have to do any design work, just assembly and maybe a little bit of improvisation due to substandard parts.