Use containers. Start with one device. Check your utilization after you’re sure you’ve hit min and max for each of your services, then figure out if your single device can handle all your services gunning at once. If not, take your biggest service and migrate it to its own device.

Eventually, you might find yourself googling “Kubernetes vs Docker Swarm.” When you do that, take a deep breath and decide if upgrading one device is easier than trying to horizontally scaling many.