It's pretty amusing how a bunch of teams are posting videos on how they built a specific, bespoke hardware/software component or two of MrBeast videos. This one was about the ~100 hardware button sets and LED strips required for the video. And here is another one [1] that is on how another team build 456 "detonator units" for the Squid Game video: also finished in the nick of time.
It seems clever for MrBeast to hire DIY YouTubers to do these bespoke jobs: it's a win-win even after the video, as they teams create their own "how we built this" video. It also gave me an appreciation for both how much work these massive videos are (we only saw one smaller part of the video, a hardware put together) and how chaotic it can all feel!