For Bluesky, there's a Starter Pack consisting of only Google DeepMind employees. Seems like a good place to start on Bluesky: https://bsky.app/starter-pack/sharky6000.bsky.social/3l7kt6x...
P.S. Just noticed there's also one for xAI: https://bsky.app/starter-pack-short/BYkRryU