Companies tend to talk about moderation capacity in terms of volume: cases per hour, backlog, coverage across time zones. The number nobody puts on a dashboard is how much the work costs the person doing it, and how quickly that cost accumulates.
I led a team of more than twenty agents whose daily work included the worst material the platform received. Over several years I learned that almost everything that helps is structural, and almost nothing that helps is a workshop.
Resilience is not a trait you hire for
The instinct is to look for people who can handle it. But the people who cope best in month one are not reliably the people still coping in year two, and treating endurance as a personal quality quietly makes it the individual's problem. It is not. It is a design problem, and design problems have design answers.
What actually worked
Rotation, first. Nobody sat on the heaviest categories continuously. Mixing case types across a shift is not a perk; it is the difference between a hard day and a compounding one.
A named senior person reachable in real time, not through a ticket. When something lands that a person should not decide alone, the gap between wanting help and getting it has to be measured in minutes.
Explicit permission to hand a case over without explaining why. If someone has to justify stepping back, they will not step back — they will push through, and you will find out about it later and worse.
The signals a manager should be watching
Not tears. Usually it is quieter than that: someone who used to ask questions and stops, decisions that get faster and flatter, humour that goes hard, a person who volunteers for the difficult queue every single time. Throughput often holds steady right up to the point where it doesn't, which is why watching the metric is not the same as watching the team.
The part managers get wrong
I got it wrong for a while by treating my own capacity as the benchmark. What I could read without difficulty on a Tuesday told me nothing about what someone else could read on their fourth consecutive week on the same queue. The job was never to model endurance. It was to build a rota where endurance is not the requirement.