Kelly Shortridge, author of "Security Chaos Engineering: Sustaining Resilience in Software and Systems" and CPO at Fastly, joins Scott for an ACM ByteCast joint episode about why security should be designed for failure rather than prevention. From airplane coffee makers causing critical failures to squirrels being the real "advanced persistent threat" to power grids, Kelly makes the case that no system is perfectly secure — and the teams that feel most in control are often the least prepared. The conversation covers metrics theater, the cost-resilience tradeoff, why software has unique advantages for simulation that we're not leveraging, and where LLMs fit (and don't fit) in security workflows.