In April last year, I developed a Python scraper that monitors several job sites and boards, and sends new STEM-related job offers to a couple of Telegram channels using a webhook. That way I'm always on top of which companies are hiring in my country, and what they are looking for in terms of positions and technology.
I also monitor LinkedIn job offers, but when a new one comes from them, I try to find the original offer on the company site itself, and then add the company's job board to my bot.
I've applied to very few interesting positions and got a couple of interviews, but that's it, haven't changed jobs yet.
In any case, I've definitely noticed that some companies post job offers and conduct interviews just with market research purposes, they probably don't intend to hire anyone in the short term, or at all.