Enterprise Cloud Migration — 6R Strategy and Real-World Costs

We hear the word “cloud” from clients more and more often. Not as a buzzword, but as a real requirement. The question is — what exactly, why, and how? After three migration projects, we have enough experience for an honest report.

6R Strategy — Not Everything Belongs in the Cloud¶

• Rehost (lift and shift): VMs to cloud. Fastest, least benefit.
• Replatform: Minor adjustments — Oracle to RDS, file storage to S3.
• Refactor: Rewrite for cloud-native services.
• Repurchase: CRM → Salesforce.
• Retire: Shut down what’s not needed.
• Retain: Keep on-premise.

80% of migration is decision-making, 20% is technical work.

Azure vs. AWS — Czech Market Realities¶

Azure is favored in the Czech enterprise market — Microsoft relationships, Enterprise Agreement, AD, Office 365. AWS is technically ahead in many respects, but ecosystem wins. GCP is virtually invisible in the Czech Republic.

TCO — Cloud Isn’t Always Cheaper¶

Lift and shift typically costs MORE. Where cloud saves: variable workloads, dev/test environments, disaster recovery. Detailed TCO calculation for a client: on-premise CZK 12.5M, Azure CZK 14.2M, AWS CZK 13.8M over 5 years. Cloud came out more expensive — the client went with cloud for agility.

Security — Clients’ Biggest Concern¶

Cloud data centers have better security than 99% of on-premise server rooms. But: shared responsibility model. A misconfigured S3 bucket = your fault. For banks: compliance mapping is mandatory; the Czech National Bank regulation requires regulator notification.

Migration Step by Step¶

1. Assessment (4 weeks): inventory, dependency mapping, 6R categorization
2. PoC (4 weeks): migrate one system, verify performance
3. Migration waves (3–6 months): gradually from least critical
4. Optimization (ongoing): right-sizing, reserved instances

Cloud Is a Journey, Not a Switch¶

Migration takes months to years. Start with an assessment, do a PoC, migrate gradually. And above all — be clear about WHY. “Because everyone else is doing it” isn’t a good enough reason.