Well the biggest "scalers" have become Cloud providers themselves. I think there's a good saying about Cloud and scaling, paraphrasing - "if you don't start on

Well the biggest "scalers" have become Cloud providers themselves. I think there's a good saying about Cloud and scaling, paraphrasing - "if you don't start on Cloud that's unwise and if you (over)stay that's insane". I guess as your solution reaches maturity and stability (no sudden swings in usage or complete changes in the architecture) then you should start thinking about some on-prem solution with maybe the hardware being leased along with maitenance.