How possible is it to spot red flags about toxic culture during the interview?

Adding on to Rahul's question (which is great), another spin on this is:

"What's the greatest challenge facing your organization right now?"

An immediate red flag is if they say that nothing's really a problem or some generic, feel-good answer like "We need to continue shipping well and figuring out the market." Answers like these mean that they're drinking the Kool-Aid, which isn't a good sign. From my experience, healthy organizations are more transparent and bottoms-up.

Another question to ask is:

"How are project deadlines set, and how does the team react when they're falling behind a deadline?"

There's 2 signals to look out for here:

1. Engineers have a say in setting the deadline as they're the ones actually building out the project.
2. The team will try other methods besides burning engineers out to meet the deadline (descope, bring in additional resources, etc).

The classic red flag answer to this question is something that is purely like: "Well, sometimes we just need to extra longer hours to get it across the finish line. That's just the way it is." This shows that leadership fundamentally doesn't value the well-being of engineers and won't make the effort to find more creative ways to achieve productivity.

I think these other discussions may be helpful:

• "How to look for red flags in the team?"
• "What questions can I ask a potential new team?"

...currently I am interviewing with some companies which their Glassdoor reviews are really low and there are pretty bad reviews in terms of culture and engineering.

From my experience, Glassdoor ratings are generally more positive than they should be. If these companies are on the larger side (>500 employees, >50 Glassdoor reviews) and the score is still low (i.e. lower than 3.5 stars), it's very likely that these aren't good places to work.

You can still interview with them for practice and to use their offers as negotiating leverage, but you should probably stay clear of actually joining these companies.

A go-to question for me:

What is your least favorite part of this job? What have you tried doing about it?

You can compare the answers with Glassdoor, and the attempts to fix it will also be telling.

Honestly I could not spot it. Things looked great on all fronts in the interview and in my interactions. It took me two years to realize that the people are not who they claim they are, and it is toxic, backstabbing. If you can find an ally or an in , you can talk to them. Ask them, how it feedback provided, how does one foster a safe environment at work , what happens one someone accidentally introduces a bug/ makes a mistake ?