Should you leave the cloud? Eight questions first.
Moving back to your own servers pays for some workloads and not for others. Answer eight questions and get a verdict, with the figures behind it: what could move, what it would cost to run, and how long before the move pays for itself.
How the verdict is decided
What could move is the steady load that does not depend on managed services. Once it runs on your servers, it costs racks, hardware and people instead of the cloud bill, and saves on the data it sends out. The verdict is stay, and optimise if that change saves nothing, or if the move takes more than 36 months to pay for itself. Otherwise it is move the steady base, keep the rest when less than 45% of the load could move, when growth is fast, or when nobody would run the hardware; and leaving can pay in the other cases.
Repatriation sits at level 7 of the method, CTO steering: cost per customer or per transaction, the cloud's share of revenue, build or buy, repatriation where it is justified.
Change the assumptions
None of these figures has a source: they are the model's assumptions, pre-filled with its defaults. Put your own and the verdict follows.
The sourced figures
| Figure | Value | Source |
|---|---|---|
| Off a bill that was only partly optimised | 35% | The typical reduction of an audit |
| Off a bill that was not optimised | 55% | The savings of the method's example |
| Data out to the internet, first 10 TB a month | $0.09 per GB | AWS Price List, EU (Paris) |
| Data out to the internet, next 40 TB a month | $0.085 per GB | AWS Price List, EU (Paris) |
| Data out to the internet, next 100 TB a month | $0.07 per GB | AWS Price List, EU (Paris) |
| Data out to the internet, over 150 TB a month | $0.05 per GB | AWS Price List, EU (Paris) |
| Dollars to euros | 0.89 | The rate of the calculator |
AWS Data Transfer offer file of September 16, 2026, read on November 9, 2026; the CloudFront article prices the same tiers. A TB counts as 1000 GB, and the 100 GB a month free are left out.
The audit puts your own figures on it.
Free, 48 hours, from your billing exports and with your negotiated discounts. I'm paid 20% of the savings measured on your bill, for 12 months, and nothing if the bill does not go down.