> They also use Reed-Solomon and split data into multiple pieces to store on multiple servers. So they need all those "load balancing"-like nodes anyway
Yes. We definitely do "load balancing" or more accurately "disk space loading balancing" but we do it all in software. The net outcome is the same, but the cost is lower.
> probably no new hardware or infrastructure is necessary to conform to S3 API
No, it would require additional hardware we do not purchase at all right now. Backblaze's philosophy is to shave off cost at all layers if it doesn't actually contribute to uptime or durability. Put differently, if there is a lower cost way to achieve the same uptime or durability with some intelligent software or possibly an extra network round trip, we do it that way instead of purchasing extra hardware.