Let me know if the 503 continues to be seen, especially with a browser refresh/cache clearing. We had a few other reports of it overnight and are investigating now.
As far as the Arduino Scheduler, we've had so many one-off bugs with it that we decided to re-write it, and are hoping to have something new to test in May. @joaoduarte_89, and you too @ognqn.chikov, would either of you be interested in being part of a private beta test of this new scheduler when it is available on a development server? If anyone else reading would like to be part of this too, please send me a PM.