I'm using one Amazon AWS free tier VPN (just 1GB RAM) just for trading and i'm running it 24/7 for 10 straight days now. CAT already made more than 147 thousand API calls and completed 218 Ping-Pongs in 3 different market tabs. My RAM use never excedes 250MB and i can see in the logs that, in my opinion, CAT it's very stable and reliable for this kind of program.