When systems work is consistently displacing selling or marketing work — usually somewhere around $10–15M ARR, because the ratio compresses to roughly one head per $12M below $25M ARR. The first hire is indivisible: you cannot buy 0.4 of a RevOps person internally.
That indivisibility is exactly why the first hire is the hardest to justify on a ratio and why fractional or partner support is common up to that point. Hire for the constraint you actually have — systems build, analytics, or process — because the generalist first hire will be defined by whichever fire is loudest.
Every claim above comes from work LeanScale published. These are the sources.