4. He felt he was docked points as he had to traverse multiple dictionaries to navigate the JSON output which was inefficient. The employer suggested a 'Tree structure' might have been better.
5. He felt he scored points by describing why Python sets are more efficient than dictionaries (for some use case).
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko