Really didn't work for me.
I can see why this got such a hot & cold reception from critics. It did some things great, and other things horribly.
The cinematography was great, and the concept was very interesting. What it got wrong? Primarily, the main characters were utterly obnoxious. Just headache inducingly unlikeable. Couldn't find anything redeemable with either of them, and thus could not get behind them at any point during this movie.
Personally, I feel this movie suffered due to Sam Esmail both writing and directing. Most movies made this way simply fall apart. It's just too much power for most movie makers to have. They go off on a tangent, and there's no one there to take them by the scruff of the neck and drag them back into line. Sam Esmail should have left the writing to someone who can actually write tolerable characters, period.
In conclusion, this movie had potential, but just didn't execute its ideas well enough. 5/10