Update README.md

Author: Joseph Luce

system_design/README.md

@@ -2,9 +2,10 @@
 Start here.
 - https://www.educative.io/collection/5668639101419520/5649050225344512
 
-### How would you design a messenger app?
-I recommend checking this guy's channel
-- https://www.youtube.com/watch?v=5m0L0k8ZtEs
+### YouTube suggestions
+I recommend checking this guy's channel (Success in Tech). I would actually avoid Tushar Roy's channel, the quality of system design isn't on par. Another possible channel is Gaurav Sen.
+https://www.youtube.com/channel/UC-vYrOAmtrx9sBzJAf3x_xw
+https://www.youtube.com/channel/UCRPMAqdtSgd0Ipeef7iFsKw
 
 ### Rest Api and HTTP
 - https://www.youtube.com/watch?v=rhTkRK53XdQ