A sophisticated computer program + highly powered computer + vpn + proxy close to seller sever + high speed internet built by smart nerds who are in this business for years. It’s basically programmed to buy a bunch of pairs in the matter of nanoseconds.
People seem to get consolation by believing that bots bought all the sneakers.
Here is the problem: you can only get one pair per account. Let’s assume that our hypothetical nerds are using Android on a VM, they still need the bot to open the app, sign in, get the sneakers, and checkout. Assuming they can pull this off with minimal or no testing, how are they creating multiple accounts? Each account requires a Google Play account AND a Nike account. Nike requires a unique phone number for each account. Do you know how many accounts they will need to buy out 35,000 pairs?
So either there are many, many hacker nerds out there, or you can just accept the fact that hundreds of thousands (maybe millions?) of people were trying to buy a few thousand pairs of sneakers and the vast majority of people didn’t get one.