Application Innovation
Application Modernization Services
Renew the legacy applications your business depends on, incrementally and without a risky big-bang rewrite, so they become faster to change, cheaper to run and ready for cloud and AI.
Keep What Works, Modernize What Holds You Back
Many core business applications were built ten or twenty years ago and still run critical processes reliably. The problem is everything around them: frameworks no longer supported, developers who know the code retiring, deployments that need a weekend of downtime, no APIs for mobile apps or partners, and security findings that cannot be fixed without touching fragile code. Each change becomes slower and riskier, and the application turns from an asset into a constraint.
Hanoi Technology modernizes applications pragmatically. We analyze the code, architecture, data and business value of each application, choose the right strategy, from replatforming to refactoring or rebuilding, and then deliver it incrementally. Patterns such as the strangler fig let new components replace old ones piece by piece while the system stays in service, so the business sees improvements early and risk stays under control.
The Challenge
Why Legacy Modernization Is Difficult
Modernization projects fail when these realities are underestimated.
Hidden Business Logic
Decades of rules are embedded in code, stored procedures and batch jobs with little documentation, and missing even one breaks real processes.
Big-Bang Rewrite Risk
Rebuilding everything at once takes years, freezes new features and often ends in delays or failure before any value is delivered.
Tightly Coupled Architecture
Monolithic applications and shared databases make it hard to change one part without affecting everything else.
Limited Test Coverage
Without automated tests, teams cannot verify that modernized components behave exactly like the originals.
Business Value
The Business Case for Modernization
Faster Feature Delivery
Modular architecture, automated testing and CI/CD reduce release cycles from months to weeks or days.
Lower Running and Maintenance Costs
Retiring unsupported platforms, expensive licenses and manual operations frees budget for innovation.
Improved Security and Compliance
Supported frameworks and modern security practices close vulnerabilities that legacy stacks cannot address.
APIs for Digital Channels
Exposed services connect core systems to mobile apps, partner integrations, automation and AI.
Better User Experience
Modern, responsive interfaces improve productivity for employees and satisfaction for customers.
Easier Hiring and Retention
Current technologies make it easier to find and keep engineers who can evolve the system.
Modernization Is a Portfolio Decision
Not every legacy application deserves the same treatment. Some should be retired, some simply rehosted, others refactored or rebuilt. Frameworks such as the 7 Rs of migration and modernization help structure these choices. We help you decide application by application, based on business value, technical condition and risk.
Our Services
Hanoi Technology’s End-to-End Application Modernization Services
Services that take legacy applications from assessment to modern, maintainable software.
Application Portfolio Assessment
We evaluate each application’s business value, technical health, cost and risk, and recommend a disposition such as retain, retire, rehost, replatform, refactor or replace.
- Application inventory and scoring
- Disposition recommendations
- Modernization roadmap and business case
Code and Architecture Analysis
We analyze code bases, dependencies, data models and integrations, and document the business rules embedded in them, using AI-assisted code analysis where it helps.
- Architecture and dependency maps
- Business rule documentation
- Technical debt assessment
Refactoring and Re-Architecture
We decompose monoliths into modular services or well-structured components, upgrading frameworks and removing technical debt incrementally.
- Target architecture
- Incremental refactoring plan
- Upgraded, modular code base
API Enablement and Integration
We wrap legacy functionality in secure, documented APIs so mobile apps, partners and new services can use it without touching core code.
- API design and gateway
- Integration layer
- API documentation
UI and UX Modernization
We replace outdated desktop or web interfaces with modern, responsive applications designed around user workflows.
- User research and redesign
- Modern web or mobile frontend
- Usability testing
Cloud-Native Enablement and DevOps
We containerize applications, introduce CI/CD, automated testing and observability, and prepare workloads for managed cloud services.
- Containers and orchestration
- CI/CD and test automation
- Monitoring and logging
Our Approach
Our Incremental Modernization Approach
We modernize in safe, measurable steps while the business keeps running.
- 01
Assess and Prioritize
We review the portfolio and selected applications in depth, and agree priorities and success metrics with business and IT stakeholders.
Deliverables: Assessment report · Prioritized roadmap
- 02
Build a Safety Net
We capture existing behavior with automated characterization tests and monitoring before changing any code.
Deliverables: Automated regression tests · Baseline performance metrics
- 03
Define the Target and Seams
We design the target architecture and identify the boundaries where new components can replace old ones gradually.
Deliverables: Target architecture · Decomposition plan
- 04
Modernize Incrementally
We replace or refactor one capability at a time, routing traffic to new components using patterns such as the strangler fig.
Deliverables: Modernized components in production · Retired legacy modules
- 05
Optimize and Hand Over
We tune performance and cost, complete documentation and transfer knowledge to your team or continue as a managed service.
Deliverables: Documentation and runbooks · Knowledge transfer sessions
Use Cases
Application Modernization Use Cases
Typical modernization scenarios we handle.
Monolith to Modular Services
An e-commerce company splits its monolithic platform into services for catalog, checkout and fulfillment, enabling independent releases.
Desktop to Web Migration
A business replaces a legacy desktop application with a web application accessible from any device.
Framework and Runtime Upgrades
An organization upgrades applications from unsupported versions of .NET Framework, Java or PHP to current releases.
API Layer for Core Systems
A financial services firm exposes core banking or policy functions through APIs to support a new mobile app.
Database Modernization
A company moves from an expensive proprietary database to a managed open-source alternative, refactoring stored procedures as needed.
AI-Ready Application Platforms
A logistics business modernizes its operational system so real-time data can feed optimization and forecasting models.
Technology
Modernization Technologies
Modern frameworks, platforms and tools that keep your applications maintainable for years to come.
- .NET 8
- Java Spring Boot
- Node.js
- React
- Angular
- Docker
- Kubernetes
- Azure App Service
- AWS Lambda
- Amazon ECS
- Google Cloud Run
- PostgreSQL
- Apache Kafka
- Kong
- Terraform
- GitHub Actions
- SonarQube
- OpenTelemetry
Platforms
Deliver Application Modernization on Your Preferred Platform
Why Hanoi Technology
Why Organizations Choose Hanoi Technology
Senior, Cross-Functional Teams
Strategy, data, AI, cloud and engineering specialists work as one team, so nothing is lost between hand-offs.
Proven Delivery
More than 50 projects delivered for clients in North America, Europe and Asia-Pacific.
Radical Transparency
A written update every week and a demo of working software every sprint, so you always know where things stand.
Cost-Effective Global Delivery
Experienced engineers from our Hanoi delivery hub, with working-hour overlap for every major time zone.
Success Story · Logistics
Route optimization and fleet visibility for a regional logistics company
A regional delivery company handling thousands of shipments a day was planning routes and dispatching by hand. We built dynamic route optimization, a fleet dashboard and a driver app.
Read the Full StoryMore Success Stories
Fintech
+162%monthly active usersAll-in-one digital banking app for a traditional bank
A traditional financial institution wanted to compete with neobanks for mobile-first customers. We replaced a set of separate banking, investing and payment apps with one product that people use every day.
Real estate
+38%lead conversion rateProperty discovery and lead conversion for a US real estate marketplace
A US marketplace connecting buyers, sellers and agents had plenty of traffic but few enquiries. We built personalized property discovery, AI valuation and a one-tap route to contact an agent.
Resources
Featured Resources
Industry trends and practical guidance to help you get more value from data, AI and technology.
FSMA 204 After the Delay: Using Shipment Monitoring to Get Traceability-Ready by 2028
The FDA Food Traceability Rule deadline moved to July 2028, but the data work is large. Here is how to use shipment monitoring and event data to get ready without wasting the extra time.
CSRD After the Omnibus: What the Revised ESRS Mean for Reporting From 2027
The Omnibus and the simplified ESRS reshaped EU sustainability reporting in 2026. Here is who is in scope, what changed in the standards and how to adapt your data and process.
OpenTelemetry in 2026: Building a Vendor-Neutral Observability Strategy
OpenTelemetry has become the default way to collect telemetry. Here is what changed in 2026 and a practical roadmap for a vendor-neutral observability stack.
Modernize Your Legacy Applications Without the Risk
Tell us which applications are slowing you down. We will reply within 24 hours and arrange a free consultation to discuss a practical modernization path.
Application Modernization FAQ
Should we rewrite our legacy application from scratch?
A complete rewrite is sometimes right, but it is the riskiest option. It requires rediscovering every business rule, freezes new features for a long time and delivers no value until the end. Incremental modernization, replacing components one by one while the system stays live, usually delivers value sooner with lower risk. We recommend a rewrite only when the existing code and architecture no longer provide a usable foundation.
What are the 7 Rs of modernization?
The 7 Rs are a common way to classify options for each application: retire, retain, rehost, relocate, repurchase, replatform and refactor or re-architect. Retiring or retaining avoids unnecessary work, rehosting and relocating move applications with minimal change, repurchasing replaces them with SaaS, replatforming makes targeted optimizations, and refactoring changes the code and architecture to gain the most benefit. We apply this framework during portfolio assessment.
How do you avoid breaking existing functionality?
Before changing code, we build a safety net of automated tests that capture the current behavior, often called characterization tests, along with monitoring of key metrics. We then modernize in small steps, run old and new components in parallel where needed and compare results. Feature toggles and gradual traffic routing allow fast rollback if an issue appears, so users are protected throughout the process.
Can you work with old technologies like VB6, classic ASP or legacy Java?
Yes. Our engineers analyze legacy code in older languages and frameworks, document its behavior and plan migration to current technologies. AI-assisted tools help accelerate code understanding and translation, but every change is reviewed and tested by engineers. For very specialized platforms, we partner with your internal experts who know the system’s history and business context.
How long does modernization take?
A portfolio assessment usually takes a few weeks. Modernizing a single application varies widely, from a few months for a framework upgrade or replatforming to longer programs for re-architecting large monoliths. Because we deliver incrementally, the first modernized components typically reach production early in the program, and value accumulates with every release rather than at a single final launch.
How do you estimate the cost of modernization?
Cost depends on code base size and quality, the number of integrations, data complexity, the chosen strategy and the level of test coverage that must be built first. We base estimates on actual code and architecture analysis rather than assumptions, and break the program into phases with clear deliverables. This allows you to fund modernization incrementally and reprioritize as results come in.