From Kagi:

“Kagi Search includes anonymized requests to traditional search indexes like Google and Bing as well as sources like Wikipedia, DeepL, and other APIs. We also have our own non-commercial index (Teclis), news index (TinyGem), and an AI for instant answers. Teclis and TinyGem are a result of our crawl through millions of domains, focusing primarily on non-commercial, high-quality content.”

“Our unique results combined from all of these sources help you discover the best content you can possibly find online, sometimes from the quieter places on the web.”

I don’t know if I would simplify it to “Google on the backend” as it’s compiling from multiple sources, including their own.