They make lots of money, free food, all the perks. I spent time building their hadoop cluster and writing spark jobs. Just to do fairly mundane things (over 10s of billions of rows), find fraudsters, ensure compliance, optimize return amounts, optimize bonus schemes.
People were mostly young (at 30 I was one of the oldest devs) lots of red tape and crappy slapdash systems. Frankly anything outside the big-data team I was on was held together with duct tape, string and bubblegum.
Nothing super unethical (apart from some of the relentless optimization I guess)
So I take it you must not have worked for Ultimate Bet.