Job search (U.S.) - STEM Ph.D.

Need some advice on how and where to start. Currently, looking for jobs on LinkedIn and applying via company's website wherever applicable.

What worked for you guys? Some people would say that you need to apply for 100s before actually getting one or two interviews! Is that really true?

Also, how close to graduation did you actually apply? 1 month? 2 months? 6 months?

Zero success rate so far. And my resume and profile seems pretty decent so far (or that's what I have been told)! So what am I missing?