For Fintech, Healthcare, and Wealth Management firms, this slow failure carries a higher price tag. Compliance mandates don't pause for technical debt. Client expectations for real-time dashboards don't care that your core system runs on a mainframe from the 1990s.
More than 85% of organizations were expected to adopt a cloud-first strategy by 2025, according to a Gartner forecast reported by TechRepublic. Yet plenty of critical, regulated workloads are still sitting on-prem, untouched.
This guide covers why migration matters now, the 6Rs framework for choosing a strategy, a step-by-step roadmap, common cost pitfalls, and how to pick a partner who won't leave you mid-migration.
Key Takeaways
- Legacy systems compound compliance, security, and scalability risks the longer they're left untouched
- The 6Rs framework matches migration strategy to business value—not a one-size-fits-all approach
- Phased migration from assessment through optimization cuts downtime and rollback risk
- Partners with domain certifications and regulated-industry experience shorten the path to production
What Is Legacy Application Migration and Why It Matters Now
Legacy application migration means moving outdated on-premise systems—mainframe ERPs, COBOL transaction platforms, on-prem CRMs—into modern cloud environments while keeping business logic and data intact.
A common example: a wealth management firm running client portfolio calculations on an AS/400 system built decades ago. The logic still works, so nobody wants to touch it. But it can't talk to modern APIs, and the two engineers who understand it are nearing retirement.
Warning signs it's time to move:
- Maintenance costs climbing year over year with no performance gains
- Inability to scale during peak transaction periods
- Security patches that are slow, manual, or simply unavailable
- No clean integration path to modern analytics or AI tools
Legacy code isn't rare. Hundreds of billions of lines of COBOL still run banks, insurers, and hospitals today. Many production legacies still trace design lineage back 60+ years, and attrition among the engineers who know them runs near 10% a year. Every year you wait, more institutional knowledge walks out the door.
Why Fintech, Healthcare & Wealth Management Firms Can't Afford to Wait
These industries carry a heavier compliance load than most. HIPAA's Security Rule requires administrative, physical, and technical safeguards for electronic health data—and that duty extends to any cloud provider handling ePHI.
SOC 2 exams assess security, availability, and confidentiality controls. Legacy on-prem systems often can't demonstrate those standards cleanly.
In a worldwide IDC survey of 2,500 developers, more than half of enterprise application estates were still legacy. Refactoring—the deepest modernization path—was the least-used technique because of its complexity. Only 6% of respondents had refactored more than 80% of an application's code.
That execution gap costs fintech, healthcare, and wealth firms real money and real risk every quarter they delay.
Common Migration Strategies: The 6Rs Framework
Not every application deserves the same treatment. Trying to rehost a mission-critical, compliance-heavy transaction engine the same way you'd rehost an internal reporting tool is how modernization projects fail. Legacy modernization projects fail about 70% of the time, largely because of mismatched strategy.
The 6Rs framework maps each application to the approach that fits its risk profile and business value:
| Strategy | What it means | Best for |
|---|---|---|
| Rehost | Lift-and-shift, move as-is | Low-risk apps needing speed over optimization |
| Replatform | Lift, tinker, and shift with minor optimization | Apps that need better cost or performance without a rebuild |
| Refactor/Rearchitect | Rebuild using cloud-native architecture | Core systems needing agility, scale, or new capabilities |
| Repurchase | Replace with a SaaS or COTS product | Apps where a modern off-the-shelf tool already exists |
| Retain | Keep in place for now | Apps not yet ready technically or contractually |
| Retire | Decommission entirely | Redundant or unused applications |
Rehosting is the fastest path to the cloud. AWS guidance recommends rehosting or replatforming first in large migrations, then tackling deeper refactoring after the initial move. Speed has a catch, though: lift-and-shift does not fix underlying architecture problems. A slow, tightly coupled application is still slow in the cloud—only now it runs on someone else's servers.
That's why a one-size-fits-all approach overspends and underdelivers. Forcing every application through a full rearchitect wastes budget on low-value systems; forcing everything through rehost leaves performance and cost gains on the table.
A mixed strategy shows what the right mapping can unlock. One large academic hospital assessed a mainframe environment—nearly $1 million a year to maintain—across 54 applications and 53 databases. By retiring legacy assets and rebuilding data access with cloud-native tools, it cut overall costs by nearly 95%.
Similar portfolio work with mixed 6Rs strategies has delivered:
- 60% faster performance
- 50% lower infrastructure costs
- Zero data loss
- 99.9% uptime after migration
Step-by-Step Process to Migrate Legacy Applications to the Cloud
A phased approach reduces the two things that kill migrations: unplanned downtime and scope creep.
- Inventory and assess every application, scoring it against business criticality, technical debt, and compliance exposure. This isn't just an IT exercise—it needs business stakeholders at the table.
- Run a cloud readiness and SWOT analysis to surface skills gaps, security exposure, and where modernization creates measurable value versus low-ROI effort.
- Select your 6Rs strategy and target platform (IaaS, PaaS, or SaaS) based on what the application actually needs, not what's trendy.
- Pilot on a representative, low-risk workload. AWS recommends a low-dependency workload, ideally non-production, to validate performance and catch integration issues early.
- Execute in phased waves, grouping dependent systems together, with rollback plans and clear stakeholder communication at each stage.
- Validate, optimize, and monitor post-migration performance, cost, and security using cloud-native tooling.
This sequence mirrors how AWS Migration Hub and Azure Migrate structure enterprise migrations: discovery, dependency mapping, wave grouping, testing, cutover, then decommissioning the source only after validation.
Map dependencies before you cut over
Dependency graphing—crawling application code to map data flows and calls—catches integration risks before they become production incidents. Automated discovery matters most in regulated environments, where an overlooked dependency is a compliance gap, not just a bug.
After cutover, keep the wave open until performance, cost, and security baselines hold under real traffic. Decommission source systems only after that validation sticks.
Cost and Challenges of Legacy Application Migration
There's no universal price tag for cloud migration. Cost depends on application complexity, data volume, and which of the 6Rs migration strategies you choose. Budgets generally break down into:
- Assessment and planning — application inventory, dependency mapping, readiness analysis
- Migration execution — the actual move, testing, and validation
- Training — upskilling internal teams on new cloud environments
- Ongoing consumption — cloud service costs, which scale with usage and require active management
Top challenges and how to handle them
These four issues surface most often in legacy-to-cloud programs:
- Architecture complexity — In Deloitte's US survey, 47% of respondents said cloud was more complex than expected. Mitigation: dependency-mapping tools before you commit to a strategy, not after.
- Data modernization bottlenecks — Legacy databases rarely map cleanly to modern schemas. Mitigation: phased, wave-based data migration rather than a single cutover.
- Talent gaps — Skilled mainframe and COBOL engineers are aging out of the workforce. Mitigation: hybrid delivery models pairing onsite architects with offshore execution teams.
- Lack of ROI justification — Leadership hesitates without clear numbers. Mitigation: pilot migrations that produce measurable before/after metrics before scaling.
Best Practices for a Successful Cloud Migration
A few non-negotiables separate smooth migrations from expensive ones:
- Back up everything before cutover. No exceptions, even for "simple" rehosts.
- Run parallel systems during transition. Keep the legacy system live until the cloud environment is fully validated.
- Migrate in waves, not one big bang. Wave-based migration limits blast radius if something breaks.
- Rehearse rollback plans, don't just document them. An untested rollback will not hold up under pressure.
- Establish post-migration governance. Pair continuous monitoring with FinOps cost visibility and recurring security and compliance audits.
The FinOps Foundation frames this as an ongoing cycle—Inform, Optimize, Operate—not a one-time cleanup after go-live.
How Hexaview Helps Enterprises Migrate Legacy Applications to the Cloud
Hexaview Technologies is an AWS Select Tier Service Partner and SOC 2 Type 2 certified, with over a decade modernizing systems for Fintech, Wealth Management, and Healthcare. Clients include firms such as LPL Financial and Addepar.
Hexaview's approach pairs domain expertise with hands-on technical execution:
- Cloud readiness assessments — map dependencies, timelines, and risk controls into a clear migration roadmap
- 6Rs strategy selection — match rehost, replatform, or refactor to each application's business value, not a default playbook
- Phased migration on AWS, Azure, Google Cloud, and Databricks, with parallel runs and rehearsed rollback plans
- Post-migration optimization for performance, cost monitoring, and ongoing compliance
In one healthcare engagement, Hexaview migrated patient data and applications to Azure while maintaining full HIPAA compliance, with zero downtime during the transition.
Need a migration roadmap built for Fintech, Healthcare, or Wealth Management requirements? Talk to a Hexaview modernization expert.
Frequently Asked Questions
What is legacy migration?
Legacy migration moves outdated, on-premises applications into modern cloud environments to improve performance, security, and scalability. You keep existing business logic and data while modernizing the infrastructure underneath.
Can you give me an example of a legacy application?
Common examples include mainframe-based ERP systems, COBOL-based transaction platforms, and on-premises CRM software. Many financial and healthcare institutions still run core operations on systems built decades ago.
What are the common strategies for migrating applications to the cloud?
Most programs use the 6Rs: rehost (lift-and-shift), replatform, refactor/rearchitect, repurchase (move to SaaS), retain, and retire. Each path balances speed, cost, and how much of the application you modernize.
What is the fastest way to migrate applications to the cloud?
Rehosting, or lift-and-shift, is the quickest method since it moves applications without code changes. It works well for low-risk workloads but doesn't fix underlying performance or architecture issues in complex legacy systems.
How much does it cost to migrate to the cloud?
Cost depends on application complexity, data volume, and migration strategy. Plan for assessment, execution, team training, and ongoing cloud consumption—and finalize ranges only after a scoped assessment.
