Amit Fulay, the Head of Product for Real-Time Communications at Google, has left the company and joined Facebook. He made the announcement on Twitter yesterday.

Fulay had a key role at building Hangouts, Allo, and Duo at Google. There’s no word on why he decided to quit — or why he was fired — and what his new role at Facebook is. His Twitter bio says he’s the “Product @ Facebook”, which doesn’t tell us much. It’s possible that he has joined the team behind Messenger, although nothing has been confirmed.

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Google hasn’t shared any info on this topic, so there’s no word on who will or already has replaced him. What’s clear is that the new Head of Product at Google has a lot of challenges ahead. Allo and Duo are both great services that get the job done, but they’re lagging behind rivals like WhatsApp and Messenger when it comes to the number of active users.