• Valve handbook (if you read between the lines)
• Working at Valve: ‘A Fearless Adventure’ or ‘Lord of the Flies’?
• Chaos Monkeys: Obscene Fortune and Random Failure in Silicon Valley

Note: I am not saying this is bad practice. These companies try to offer you the best work environment and a very good salary. If you like working then this right for you and it will not necessarily feel like work. Also things might have changed in the last few years at Meta.