That's not exactly how it works. Development doesn't freeze - change requests, PRs, etc. can all be rolled in right up to the end and even after release if the

That's not exactly how it works. Development doesn't freeze - change requests, PRs, etc. can all be rolled in right up to the end and even after release if the appropriate process is followed, and in software, even in a safety critical world, you can pipeline updates out in a reasonably fast manner (we can get it down to about two weeks for minor updates). Hardware is an entirely different beast. You have to do FPGA development and prove-out, gate-level sims, timing accurate sims, thousands and thousands and thousands of simulated testbenches (hardware sim is orders of magnitude slower than software sim - hours per second, even on the most advanced equipment). Therefore, each testbench must be developed to test a very specific thing - in general, you can't just run your high-level software unit tests. Anyway, even if Tesla is the kind of company to roll software (doable) or boards (doable, but harder) right up to the last minute ... they do not (and neither does anybody else) spin a chip over and over again during the course of the development cycle. Speaking as the lead of a SW team that proved out a safety-critical custom SOC, it is colossally expensive. Every single iteration takes many months and millions of dollars.