My standard procedure when looking at job listings is to search references of the company on HN, to see if there's any chitchat about its services/products.
Just 2 months ago I found a LI listing for a company that even has a "Show HN" - "...one of the fastest-growing security and compliance platforms in history." Not much chatter about it, but enough I felt assured to apply to the listing.
It's only after I clicked Submit that I discovered a factoid on the LI listing: it had been open for NINE months. The company's ATS does not show time-of-posting.
Worse-- just right now, I went to both the company's ATS listing and Linkedin: the posting is still open, 11 months now and counting.
Oh, and no surprise-- no response to my application, two months later.