The story goes that when Tesla was new, no one wanted to work with them since new auto companies generally fail, and it was EVs at that. Additionally, there wasn’t a supply chain to support EVs either.

So in addition to setting up new supply chains (which did involve overseas stuff) they ended up making a lot of their own things, becoming very vertically integrated from the start. That learning to support themselves has persisted ever since.

They were always pretty focused on keeping the supply chain as local as possible as that reduces all the shipping costs. There are actually parts you could buy overseas for $X but when you look at the life cycle of that object it’s actually gone around the world many times before it becomes what you want. You can save a lot of money if you find a way to avoid that. That could for example involve finding a raw material company locally, and then convincing a local manufacturing company to build this new thing for you using raw materials from the other local company. It’s not simply oh we just find someone already making this existing thing in USA instead of China (but it can be that too), it’s actually putting the supply chain and manufacturing capacity together so it becomes local.

It’s probably one of the biggest reasons why they make more money on their EVs than others.

They’ve literally built a lithium refining facility as an example of the level of vertical integration they have. They plan to extract their own lithium in the future (they own land in Nevada with it), refine it themselves (this year), they build their own cathode, and put it into their own battery cells.