Planning a Cloud Migration? Don’t Forget These 5 Post-Migration Pitfalls

Cloud migration is a major milestone for any business, but it’s not the finish line. According to Gartner, more than 80% of organisations that move to the cloud will overspend on their post-migration environment by the end of 2025, due to poor optimisation and planning. The problem isn’t the move itself; it’s what happens after.

Many businesses spend months preparing their cloud strategy, only to hit new roadblocks once systems are live. From cost sprawl to performance issues, post-migration mistakes can quietly undo all the benefits you expected from the cloud. Here are five of the most common post-migration pitfalls and how to avoid them.

1. Assuming Migration = Optimisation

Just because your systems are now hosted in the cloud doesn’t mean they’re cloud-optimised. In fact, many workloads are moved as-is from on-prem environments to cloud, without being adapted to take advantage of cloud scalability and cost-efficiency.

Unless these workloads are properly reconfigured for the new environment, you may find yourself running old problems on newer platforms, only at a higher cost. It’s a common trap. Virtual machines are lifted and shifted as-is, services are overprovisioned “just in case,” and teams leave test or backup environments running long after they’re needed. The result? Soaring bills, inconsistent performance, and no clear ROI.

What to do instead: conduct a post-migration performance and cost audit. Use monitoring tools to right-size resources based on actual usage. This ensures you get the full benefit of the cloud, not just the invoice.

2. Neglecting Cloud Governance and Access Control

It’s common to open up access during migration for speed, but leaving that access wide open can become a serious risk later. Without clear governance, teams may spin up unnecessary instances, store data in the wrong regions or bypass security protocols.

Make sure you have:

• Defined access roles and MFA in place
• Guardrails for data handling and backups
• Visibility over who is doing what, where

Pro Tip: Governance frameworks like the Well-Architected Framework or NCSC’s Cloud Security Principles can help set standards from day one.

3. Overlooking User Training and Change Management

Cloud migration often comes with new tools, new processes and new ways of working, but users aren’t always equipped to make that shift. If staff continue using cloud systems like they used their on-prem ones, you risk losing time, data and confidence. This is particularly true in fast-paced environments like retail and hospitality, where IT teams need simple, reliable systems that just work. Without guidance, you’ll see frustration rise and helpdesk tickets pile up.

What to do: Build training into your migration plan, not after it. Offer short, practical sessions tailored to each user group, and create quick-reference materials that explain what’s changed. Keep communication open post-migration so users can flag issues early and adapt faster.

4. Failing to Review Security Posture

While cloud platforms offer robust security features, they don’t configure themselves. Many businesses assume security is baked in, but miss the fact that data access, identity protection and device security are still their responsibility. This becomes even more complex in hybrid environments, where on-prem and cloud systems must work securely together, and where overlooked gaps can become easy entry points for attackers.

What to do: Conduct a full post-migration security review. Reassess user access policies, endpoint protection, backup encryption and alerting configurations. Use tools like Microsoft Secure Score or AWS Security Hub to benchmark your posture and highlight gaps.

5. Not Setting a Process for Ongoing Optimisation

A cloud migration isn’t a one-time project. It’s an evolving environment that needs regular review to stay cost-efficient and high-performing. Yet many businesses fail to revisit their setup until something goes wrong.

Create a cadence for:

• Reviewing monthly usage and cost reports
• Reclaiming unused resources
• Updating configurations based on changing needs

Put a schedule in place to review your cloud estate at least quarterly. Track usage, decommission unused resources and explore opportunities to adopt cost-saving tools. A trusted managed services partner like Retail Assist can help manage this on your behalf and flag issues before they grow.

A Migration Plan Is Only Half the Story

A successful cloud migration doesn’t end at go-live. In fact, the most value comes after the move, when you fine-tune performance, tighten controls and ensure the environment truly works for your users and your bottom line. At Retail Assist, we help businesses plan beyond the migration itself. From cloud readiness to ongoing optimisation, our managed services team ensures your investment pays off.

Need a second opinion on your cloud setup? Let’s talk about making it work better post-migration.

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