Cloud Migration 101: What to Know Before Moving Your Infrastructure

Cloud Migration Is Not a Lift-and-Shift

The most dangerous cloud migration myth is that you can simply move your existing servers to the cloud and reap the benefits. Organisations that take this approach, known as lift-and-shift, typically find their cloud bills higher than their previous data centre costs, with none of the agility benefits they anticipated.

Cloud migration done right is a re-architecture exercise, not a relocation project.

The Six Migration Strategies (The 6 Rs)

AWS popularised a framework that remains the industry standard for migration planning:

1. Rehost (Lift and Shift), Move servers as-is. Fast, but misses cloud-native benefits. Suitable for legacy applications nearing end-of-life.

2. Replatform, Move with minor optimisations (e.g., switch to managed database). Moderate effort, good value.

3. Refactor / Re-architect, Redesign for cloud-native patterns (microservices, serverless, containers). High effort, maximum benefit.

4. Repurchase, Replace with a SaaS alternative (e.g., move to Salesforce, replace on-prem HR system with Workday).

5. Retain, Keep on-premises for now (compliance, high refactoring cost, upcoming end-of-life).

6. Retire, Decommission, up to 30% of an enterprise estate is often found to be redundant.

What to Do Before You Migrate

Discovery and Assessment

Inventory every application, its dependencies, its data flows, and its compliance requirements. Tools like AWS Migration Hub, Azure Migrate, or purpose-built discovery agents automate much of this. Do not skip it.

Total Cost of Ownership Analysis

Cloud cost calculators are optimistic. Build your TCO model with realistic assumptions about data egress, reserved instance commitments, licencing changes, and operational overhead. Engage a cloud cost specialist if this is your first large migration.

Compliance and Data Residency

Identify all data sovereignty and regulatory requirements upfront. Choosing the wrong region or misconfiguring data storage can create compliance exposure that is expensive to remediate post-migration.

Network Architecture

On-premises networks typically have low-latency, high-bandwidth internal connections. Cloud networking has different characteristics. Re-architect your application communication patterns to minimise cross-service latency and data transfer costs.

The Migration Wave Approach

Do not migrate everything at once. Organise applications into migration waves:

• Wave 1: Low-risk, low-complexity, non-critical workloads, build the team's cloud muscle
• Wave 2: Medium complexity core workloads
• Wave 3: Complex, business-critical, tightly-coupled systems

Each wave delivers learnings that reduce risk for the next.

Post-Migration: FinOps Is Not Optional

Cloud cost management (FinOps) must be in place from day one. Without tagging governance, rightsizing policies, and reserved instance planning, cloud bills will overshoot your projections by 30–50%.

Conclusion

Cloud migration is a strategic programme, not a technical project. Invest in thorough discovery, choose the right strategy for each workload, manage costs actively, and migrate in waves. Done this way, cloud becomes the competitive advantage it promises to be.