Quick Summary: One scale per company. Every benchmark on every career, and every achieved grade, references a rung of this scale by id. Read-only over the API — the scale locks once any grade is in use.
Attributes (per rung)
Why the API never returns a bare benchmark integer
A rung carries two integers — its id and its grade value — and they routinely differ. A barebenchmark: 4 could denote a rung whose actual grade is 2, and an integrator would compute gaps against the wrong number silently. The API therefore always returns the resolved rung: { id, grade, label }.