When engineering teams take on a new project, they often optimize for performance, availability, or fault tolerance. More experienced teams can optimize for these properties simultaneously. Now add an additional property: feature velocity. Mental models of architecture can help you understand the tension between these engineering properties. For example, understanding the distinction between accidental complexity and essential complexity can help you decide whether to invest engineering effort into simplifying your stack or expanding the surface area of functional output. Chaos Engineering was born within this conflict between feature velocity and increasing complexity. Rather than simplify, Chaos Engineering provides a mechanism for you to embrace the complexity and ride it like a familiar wave, maintaining our business priorities while dialing up feature velocity.