What's your workflow with lots of 4K ProRes footage? Internal RAID, external? SAN?

As the title suggests, I'm looking for a storage/workflow solution with lots of ProRes footage. I recently bought an external recorder (Atomos Shogun Inferno) which increased my storage needs dramatically. How do you handle big file sizes for both, editing and long term storage?

I was looking at external RAID drives but the only feasible solution with enough throughput seems to be Thunderbolt based which my PCs don't have (yet).

How do you handle the need for large and fast storage?