Cloud migration promises cost savings, scalability, and innovation. But the reality? Many organizations face surprise costs that undermine ROI.
In 2025, controlling migration expenses requires a FinOps mindset and proactive planning. Let’s explore the hidden costs most teams overlook and how to mitigate them.
1. Data Transfer and Egress Fees
Cloud providers often charge for:
- Moving data into the cloud (ingress).
- Moving data between regions.
- Moving data out (egress).
Example: Migrating 50TB from on-prem into AWS may incur egress fees from your data center plus ingestion costs on AWS.
How to avoid it:
- Use offline transfer appliances (AWS Snowball, Azure Data Box).
- Compress or deduplicate data before transfer.
- Stage migration in-region to reduce cross-region fees.
2. Dual-Run Environments
During transition, many companies run old and new systems in parallel. Costs include:
- Double licensing fees.
- Storage duplication.
- Extra staffing.
Mitigation:
- Shorten dual-run windows with robust testing.
- Automate cutover validation.
- Decommission legacy faster.
3. Oversized Infrastructure
Teams often over-provision cloud resources “just to be safe.” This leads to inflated monthly bills.
Solution:
- Implement right-sizing post-migration.
- Use auto-scaling and tiered storage classes.
- Review with cloud cost analysis tools (CloudHealth, CloudZero).
4. Inefficient ETL/ELT Pipelines
Poorly optimized pipelines consume excessive compute:
- Overuse of staging areas.
- Repeated transformations.
- Non-parallelized workloads.
Fix:
- Use pushdown processing (delegate compute to warehouse engines).
- Adopt ELT pipelines with dbt where possible.
- Continuously monitor query costs.
5. Downtime-Related Business Losses
Even small outages can:
- Halt transactions.
- Delay reporting.
- Damage customer trust.
Prevention:
- Adopt zero-downtime migration strategies.
- Use CDC to sync data in real time.
- Test rollback procedures before cutover.
What Is CDC in This Context?
CDC stands for Change Data Capture. It’s a method for capturing only the inserts, updates, and deletes in your source database and applying them to the target system. Instead of reloading full datasets, CDC keeps the target continuously synchronized with minimal lag—making it essential for zero-downtime migrations.
6. Post-Migration Optimization Gaps
After migration, many teams forget to revisit their architectures:
- Workloads remain oversized.
- Legacy schemas slow down performance.
- Security roles lack fine-grained controls.
Recommendation:
- Run quarterly cloud optimization audits.
- Adopt FinOps governance for ongoing cost control.
- Train engineering teams on cost-aware design.
ROI-Centered Migration Planning
To keep migrations profitable:
- Build TCO models before starting.
- Benchmark workloads pre- and post-migration.
- Establish ongoing monitoring with business KPIs.
Conclusion
Cloud data migration can deliver massive value, but only if costs are anticipated and actively managed. By planning for egress, dual-runs, oversized infra, and pipeline optimization, organizations can maximize ROI.
Our consultants design migrations with cost optimization and scalability in mind. Learn more at our ETL Data Migration Services.
Eiji
Founder & Lead Developer at eidoSOFT