strong python (we build our show control on non-blocking I/O frameworks like tornado, also we do a lot of python within touch designer), strong database (sql, postgres, mongo), strong cms (often just django, but increasingly some html & js to sex it up)
server set up and admin, local ubuntu boxes or aws, running AMP, node, etc
has got to be creative and improvisatory, but rigorously technical
has got to love sticking things together – this person makes the glue for our rube goldberg machines