https://www.fastcompany.com/91519302/byd-nail-test-why-this-54-billion-innovation-is-terrifying-western-auto-executives

"BYD did not decide one morning to build the fastest car on Earth. First, it built phone batteries. Then E-bike packs. Bus systems. Delivery vans. Passenger cars. Hypercars. Each rung taught something the previous rung could not. There was no quantum leap. Only the next rung.

And Wang’s deepest insight had nothing to do with batteries. It was about knowledge. If you cannot reproduce a defect one hundred times, identically, you do not understand the mechanism. Do not settle for a plausible explanation. Demand a reproducible one. The difference between the two is the difference between an organization that keeps making the same mistake and one that never makes the same mistake twice."