What could make one programmer better than another is the experience on the shop floor. Programmers who have experience operating on CNC machines, have a better understanding of the programming and tend to outperform the rest. A good programmer has the experience and knows the machine’s capabilities. They would understand how far they can push it and understand the engineering behind the part. A good programmer tends to work closely with the engineers and quality inspectors to fix the issues they might come across and generate the best outcome. A good programmer would be on the ground working with engineers and machinists down the line to have a more holistic view. Distinguishing a good programmer versus a bad one requires some vetting.