Excellent Analysis of the Boeing 737 Max Software Problems
This is the best analysis of the software causes of the Boeing 737 MAX disasters that I have read.
Technically this is safety and not security; there was no attacker. But the fields are closely related and there are a lot of lessons for IoT security — and the security of complex socio-technical systems in general — in here.
EDITED TO ADD (4/30): A rebuttal of sorts.
EDITED TO ADD (5/13): The comments to this blog post are of particularly high quality, and I recommend them to anyone interested in the topic.