New Hires: Learn how the system breaks

I hope I remember this advice when I next start a new role:

Onboarding into mature systems often can be an extremely daunting, many month (or year) process. This is true for both managers and [engineers]. Failure streams are a short circuit to understanding the system, because failures are where the system is interesting and nuanced. Failures are where the heart of complexity, entropy, and flux in the system are.

Understanding failure modes helps you understand a system more quickly while simultaneously revealing high impact areas to work in. What a great piece of advice on how to start building trust with a new team.