What I think many people fail to recognize is that all aircraft vendors outsource quite a bit and have for a long time. Neither Boeing nor Airbus make the avio

What I think many people fail to recognize is that all aircraft vendors outsource quite a bit and have for a long time. Neither Boeing nor Airbus make the avionics. They buy them on spec from Honeywell or Smiths. Back when I was a DS9 working in the ASL, we’d sometimes use a full software stack to try something out with pilots and airlines. But the result was a spec that went to Honeywell for implementation. And then when we got their output, we’d put those hardware boxes into our engineering sims and see if everything matched up.