Agents of chaos are the engineers who’ll be designing and running the actual experiments. For a team’s first Chaos Day, these people should be two or more of the most experienced engineers on the team(s). If several teams are involved, then take the most experienced engineer from each team. This has two benefits. Firstly, it uncovers knowledge gaps within the team, because these engineers are non-contactable during the Chaos Day itself. Secondly, the experiments they design tend to more realistically reflect real-world failures as well as explore system failure modes less known to other engineers.