1. First we need to arrive at the architecture regarding how the system will be deployed and why it is the best approach.
2. Does the spark application required to go through firewall. If so will it have any impact on performance. If not, will it compromise security.
3. How easy is it to install and use in both desktop and mobile.
4. Hardware, O/S requirements.
5. Can it work with multiple O/S clients.
6. Do we need to implement active directory or its equivalent first if we need to use it LAN environment and also remotely.