I'm ex-AWS. Actually an ex-AWS hiring manager. My experience is at odds with the negative stories. What Amazon has is a culture with a strong flavour. Like all strong flavours, I think you're going to either love it or loathe it.
I had a fantastic team to work with - they were all either ex-tech-sector CTOs or equivalent or they had that level of potential. So as the team manager I had permanent case of imposter syndrome. My manager was the kind of engineering leader you want to be, a listener first and foremost, smart and principled and demanding but not harsh. The technology is all the more mind-blowing when you look under the bonnet. The culture and corporate structure is remarkable and in my opinion a major strategic factor in the Amazon success story. We were always hiring, all the time. When you have such strong ICs, they don't want anything less than A-list peers. As an AWS manager I allocated roughly a third of my time to hiring and promotion, and more during certain internal cycles.
So it was hard work in a demanding environment but I loved it, and that made stepping away all the more difficult. Would I return? If my startup tanked, in a heartbeat, if they'd have me back.
I also think that those who loathed it are far more vocal than those who loved it. Part of the culture is a strong sense of nondisclosure, and if you have positive memories of the place, that's going to carry over.
I will say, the hiring process described may differ between teams. There are consistencies that the recruitment folks systematically enforce, but as a hiring manager (at least in my region) we had latitude to vary screening steps and the mix of the in-person interviews. I didn't futz with it much though, to avoid screwing up procedural fairness.
I am not surprised this author got an offer, they seem bright enough, and engaging with the process and the company with genuine interest and an open mind (without trying to game it) is definitely a very positive framing and I imagine this came across in person.