Well back when I participated they were actually just a bunch of volunteers/hobbyists doing it in their free time. Not sure if a part of it has been professionalized by now. But yea, it's all very slick.

Did you know about https://habhub.org/ ? They have a predictor too for actual launches. I’ve used it to launch three balloons years ago.

https://predict.sondehub.org/

And the live tracker for actual balloons

https://tracker.sondehub.org/