Currently stealth company whose founders who went to google

MantleBio matches the query because it is currently operating in stealth mode (as indicated by the lack of public information and specific details about its operations) and one of its co-founders, Madeline Schade, previously worked at Google.

Chima is currently operating in stealth mode and one of its founders, Kiara Nirghin, previously worked at Google.

Dialect is founded by former Google engineers and is currently operating in stealth mode.