2 min lesson
Waterfall enrichment
Answer this: "You have two providers for company headcount. Provider A costs $0.02 and fills 10% of records; Provider B costs $0.10 and fills 70%. Which goes first in the waterfall and why?"
Step 1 of 3
No single data provider knows everything. Waterfall enrichment is the answer: try providers in sequence until a field is filled and you routinely double or triple the match rate of any one vendor.
This is the single most likely thing the practical round asks you to build. A Clay-style table where a domain comes in and a rich, scored profile comes out is the canonical GTM Engineer exercise and the waterfall is its engine.
Interactive diagram. Step through it with the Next and Previous controls below, or Tab to a region to read its detail.
Most records stop early; the cache and the confidence check are where cost is won or lost.
Learn more
Full explanation
Order by cost ÷ hit-rate, not just price
The right ordering isn't cheapest-first or best-first alone. Rank providers by expected cost to fill the field, which blends price with hit-rate: a $0.10 provider that fills 70% of records beats a $0.02 one that fills 10% once you count the fall-through calls the cheap-but-weak vendor forces downstream. Saying this out loud is the difference between "I've used Clay" and "I've tuned a waterfall against a real bill."