I have 20 years of experience, and also keep getting spammed.

I think that applying directly to companies is the worst possible approach. That already sets the playing field where many people are competing for one position. On top of that, many companies are not even serious about wanting to hire someone, they just keep the old announcement online because they forgot to take it down, or because who knows maybe one day a genius willing to work for peanuts will randomly appear, in which case I guess we would find some work for him.

The lesson from You Are Not Hiring the Top 1% [LW · GW] also applies here. Just like the best programmers get the job, and the worst programmers keep applying, getting rejected, and applying again (and therefore are overrepresented at the job market), also the best companies find people to fill the roles quickly, and the worst companies keep losing their employees and need to recruit new ones all the time (and therefore are overrepresented at the job announcements).

In my experience, the best way to find a job is to be recommended by a friend who already works there. The second best way is to contact a job agency and let them find the job for you.