Simon Willison’s Weblog

Having worked inside AWS I can tell you one big reason [that they don't describe their internals] is the attitude/fear that anything we put in out public docs may end up getting relied on by customers. If customers rely on the implementation to work in a specific way, then changing that detail requires a LOT more work to prevent breaking customer's workloads. If it is even possible at that point.

— TheSoftwareGuy, comment on Hacker News