Migrating a monolithic ERP landscape to the cloud

Starting point & goal

An energy utility from the DACH region ran its grown ERP landscape on its own hardware — 14 tightly coupled legacy services that were becoming increasingly expensive and risky to operate. The goal: migrate to the cloud without a single outage in day-to-day business.

Challenges

• 14 tightly coupled services without complete documentation
• No downtime windows: 24/7 operations with high availability requirements
• Historically grown data sets with complex dependencies
• The team was to take over operations itself after the migration

Implementation

We analysed the landscape service by service, containerised it and migrated it to Kubernetes — strangler pattern instead of big bang. A GitOps pipeline made every step traceable and reversible; load tests and shadow traffic safeguarded every cutover. In parallel, we trained the client's team, which runs operations independently today.

Tech stack

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