When sourcing from a Nike-level factory or a high-end OEM in China, you must prioritize technical manufacturing capabilities and compliance. Look for factories that utilize automated cutting machines, computerized stitching, and cold-cementing technology for footwear. Ensure the supplier holds ISO 9001 for quality management and SA8000 or BSCI for social accountability, as these are standard for top-tier athletic brands. It is essential to verify if they have a dedicated R&D department capable of handling 3D pattern making and material innovation.