I had the same impression, particularly driven by these quotes:
From this day on, I was even more disappointed — both with myself and tech hiring process — rejection, rejection, rejection. It honestly feels as if I am a complete failure and an unhirable candidate. How is this possible — I have received emails from people all over the world, who praise and give me thanks for the work I’ve done on my open-source projects and tutorials (and I say this as humbly as I can); people who see me as an expert on Hackhands; co-workers, friends and acquaintances from meetups, hackathons, conferences who apparently think I am a decent programmer—but I cannot pass a single tech interview. How?
TBH, the author sounds like someone who went to the interviews completely unprepared, believing that just because they have some open-source projects and tutorials, they deserve to be hired.
Nobody deserves anything. Most of my friends who went up for interviews with FAANG (or whatever is the latest acronym) studied and prepared for months even before applying.