My strategy was always the same, ask technical questions and go deeper with each question until the applicants says something like "I don't know but I would do

My strategy was always the same, ask technical questions and go deeper with each question until the applicants says something like "I don't know but I would do xyz to find out." But I always warn first that there's no problem if they don't know the answer so they know first-hand they can say I don't know. Very easy to detect bullshitter that will invent stuff or those on the first level of dunningkruger. And the best moment of my life was when I interviewed someone who had all the answers and the explanation of why it was working this way. I told hr that we had to hire him in a higher position than me!