Source
Training Data — Parallel’s Parag Agrawal: Building a New Web for AI Agents (August 25, 2026) ·
at 10:17 ▸ ·
at 19:38 ▸
When this applies
when building any system that must filter an enormous candidate set down to a tiny, highest-value output under strict cost/latency budgets
The takeaway
Use a funnel of increasingly expensive, increasingly precise filtering stages so that compute is concentrated only on the shrinking set of plausible candidates, not spread evenly across the whole search space.
Why it works
By layering query understanding, multiple specialized indexes (fresh, structured/knowledge-graph, big general index), and successively larger ranking models, compute is spent efficiently — cheap filters eliminate most candidates before expensive, precise models evaluate the remainder.
One level up
Any extreme-scale narrowing problem (billions to few) should be solved via progressive, cost-aware filtering stages, not a single monolithic model.
Where it stops holding
This stops working when the cost of maintaining multiple specialized indexes and layered models exceeds the value gained from the marginal precision improvement, or when latency budgets shrink below what a multi-stage funnel can support.
Detail
procedure:- Run initial models to interpret and enrich the incoming query
- Route the enriched query to multiple specialized indexes (big general index, fresh index, structured/knowledge-graph index)
- Apply a retrieval layer per index to narrow hundreds of billions of documents to thousands/tens of thousands
- Apply successive ranking layers with progressively bigger, more feature-rich models
- Allocate different compute/latency budgets at each stage depending on the API tier (e.g., 200ms vs 3s)
benchmarks: {"latency_improvement":"from three seconds down to 200 milliseconds","final_output_size":"about a thousand tokens from a trillion web pages"}
rationale: Every query is effectively 'give me a thousand tokens from a trillion web pages... and make sure they're the right thousand tokens.'
In their words
Like that's the query that we are getting effectively from to our search engine. And so now what you have to do, and until last week, we would give ourselves three seconds to throw a bunch of compute at read time to do it. This week, last week, we shipped a product which now does it in 200 milliseconds, right?