system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] The Empire is a galaxy-spanning government with advanced technology at its fingertips. So why do they use slaves to build their death Stars, when machines and nano-tech build in a cheaper, faster, and more efficient manner?
gpt
What nanotech is available is very expensive and typically single purpose applications.  It's not suitable for use on large scale construction projects.  
The Empire does employ quite a bit of construction machinery,  where appropriate.  Despite that, there do remain some tasks where a humanoid is the most efficient way to get the job done.  
Then there is the political aspect.  Slavery is a powerful way to control certain populations, so the Empire will take a small efficiency hit to their construction projects in order to gain those benefits.