Comment by dlcarrier

Good hierarchical documentation

A laptop computer is extremely complex, but is actively developed and maintained by a small number of people, built on parts themselves developed by a small number of people, many of which are themselves built on parts themselves developed by a small number of people, and so on and so forth.

This works well in electronics design, because everything is documented and tested to comply with the documentation. You'd think this would slow things down, but developing a new generation of a laptop takes fewer man hours and less calendar time than developing a new generation of any software of a similar complexity running on it, despite the laptop skirting with the limitations of physics. Technical debt adds up really fast.

The top-level designers only have access to what the component manufacturers have published, and not to their internal designs, but that doesn't matter because the publications include correct and relevant data. When the component manufacturer comes out with something new, they use documentation from their supplier, to design the new product.

As long as each components of documentation is complete and accurate, it will meet all of the needs of anyone using that component. Diving deeper would only be necessary if something is incomplete or inaccurate.