How happy are all the interviewers to answer your questions about the company? If half / most of them are impatient with your questions, you have a negative signal.
How do people who have left the company (can find them on LinkedIn) rate the company?
How does your hiring manager (ideally your to-be manager) handle difficult questions on attrition, burnout, team culture and work-life balance?
Finally, your gut instincts also play some role. After interacting with the recruiter and all the interviewers over many rounds, you will have a subconscious image of what it's like to work with these people. If you don't, ask to speak with your to-be team members / manager and get more data points for your subconscious.