Multi-Engine Aggregation
Combining results from more than one search engine or provider into a single ranked list.
What it means
Different search engines index the web differently and rank the same content differently, so querying more than one engine (or provider) for the same question and merging the results can surface relevant content that any single engine alone would have missed — at the cost of needing a merge strategy, since two engines' rank positions aren't directly comparable numbers.
In practice
A research agent querying both a Google-backed SERP API and an independent-index provider like Brave for the same topic might get seven overlapping results and three unique to each engine — the three unique-to-Brave results, sourced from an index built independently of Google's crawl, can surface content a Google-only search missed entirely.
Tradeoffs
Merging result sets naively (interleaving by original rank position) treats each engine's position-1 result as equally strong, which isn't necessarily true; a more careful merge weighs engines differently or deduplicates by URL first, but building that logic well is nontrivial extra engineering versus just picking one engine and living with its blind spots.