My last FAANG team had a soft 4-hour review SLA, but if it was a complicated change then that might just mean someone acknowledging it and committing to reviewing it by a certain date/time. IIRC, if someone requested a review and you hadn't gotten to it by around the 3-hour mark you'd get an automated chat message "so-and-so has been waiting a while for your review".
Everyone was very highly paid, managers measured everything (including code review turnaround), and they frequently fired bottom performers. So, tradeoffs.
Everyone was very highly paid, managers measured everything (including code review turnaround), and they frequently fired bottom performers. So, tradeoffs.