AmazingHiring.com is a People Aggregator that has recently made a debut in the US. Like the majority of aggregators, it concentrates on finding technical candidates. It is paid, as all other aggregators are. If you are in the market for one, there is a variety of aspects to consider, that depend on both the functionality and aggregated data – and I don’t think there’s one solution for all in the “aggregation” category.
The way AH stands out though is the special option to search for people with no profiles on LinkedIn or shallow profiles, that don’t have “the right” keywords. (I recall seeing a similar option in an early version of SwoopTalent). In my own tests, using this flag in AH combined with search terms, I was finding people with LinkedIn profiles that had not been updated for years, who nevertheless were viable potential candidates for the target skills. So – you might want to give it a try (contact the folks at AH).