Key challenges and solution for migrating oracleform to Angular

Key Challenges & How We Handled Them

1. Business Logic Locked in Forms & PL/SQL

• Challenge:Oracle Forms often embed complex validations, triggers, and calculations inside the form itself or inside PL/SQL stored procedures. These are hard to discover and map.

• Solution:

  • Reverse-engineer: Use Oracle Forms2XML or Ora2Pg to extract metadata.

  • Created a business rules catalog documenting validations, dependencie.

  • Collaborate with SMEs: Walk through the functionality with business users to validate extracted rules and took their signoff.

  • Refactor: Re-implemented business logic as REST APIs in Spring Boot using DDD principles for clean separation.API can be used across channels (web, mobile, APIs).

  • Unit-test: Validate correctness by comparing outputs with legacy system.

2. Stateful UI → Stateless Web

• Challenge:Oracle Forms maintain state (session-based), but Angular + REST APIs are stateless.

• Solution:

  • Introduce API gateways and JWT-based session tokens.

  • Use client-side state management (NgRx/Redux) for workflows and form states.

  • Design APIs to return minimal but sufficient data for front-end orchestration.

    
    

3.UI/UX Modernization

Challenge:Oracle Forms are not responsive and follow a transactional, form-heavy paradigm.

Oracle Forms have canvas, tabs, LOVs, and master-detail blocks, which don’t directly translate to Angular components.

End-users were used to certain shortcuts and workflows, so UX changes had to be gradual and intuitive.

Solution:✅ User-Centric Design

• 
  

  • Conducted UX workshops to identify pain points in existing UI.

  • Designed responsive Angular screens using Material Design with better navigation, search, and filtering.

  • Added keyboard shortcuts and hotkeys where possible to maintain user productivity.

  • Used component-driven design – reusable Angular components for (LOV → dropdown, canvas → grid layout). date pickers, etc.

  • Define Angular component library 

  • Use Material Design or PrimeNG for enterprise-grade UI controls.

  • Standardize UI templates for consistency and accessibility (WCAG compliance).

4. Tight Coupling with Database

• Challenge:Forms directly access DB tables, bypassing abstraction layers.

• Solution:

  • Introduce a service layer (Spring Boot microservices).

  • Encapsulate database calls into APIs.

  • Gradually deprecate direct DB calls and enforce access through APIs only.

5. Performance Optimization

• Challenge:Oracle Forms work with bulk fetches & server-side processing. Angular + REST APIs may introduce latency.

• Solution:

  • Enable pagination, lazy loading, and caching at the API and UI layer.

  • Optimize DB queries (indexes, execution plans).

  • Introduced caching (Redis) for reference data and LOVs.

  • Built REST APIs with pagination, filtering, and async calls to avoid UI freezes.

  • Use async/non-blocking APIs to improve throughput.

6. Validation & Regression Testing

• Challenge:Risk of breaking business-critical workflows during migration.

• Solution:

  • Build automated regression test suite (Selenium, Cypress for UI + JUnit for API).

  • Compare results of new system vs. legacy system side-by-side.

  • Conduct UAT with real business scenarios.

7. Security & Role Mapping

• Challenge:Oracle Forms use database roles. Angular needs app-level RBAC.

• Solution:

  • Implement centralized Identity & Access Management (Azure AD / Keycloak).

  • Map old DB roles to application roles, implement fine-grained authorization in APIs

  • Implemented OAuth2 + OpenID Connect (Azure AD / Keycloak).

  • Applied role-based access control (RBAC) at API and UI component levels.

  • Added audit logging for compliance (important for BFSI).

8. Change Management & User Adoption

• Challenge:End users are familiar with Oracle Forms UI (keyboard shortcuts, workflows).

• Solution:

  • Provide training sessions and sandbox environments for users.

  • Ensure UI parity with legacy system wherever possible before enhancing UX.

  • Implement feedback loop during pilot rollout.

9. Parallel Run & Data Consistency

Challenge:During phased rollout, some users used Oracle Forms while others used Angular UI. Data consistency and synchronization were critical.

Solution:✅ Coexistence Strategy

• Enabled dual-write mode for APIs.

• Built data reconciliation jobs for early detection of mismatches.

• Conducted parallel UAT before cutover.

  
  

10. Authentication & Authorization

Challenge:Oracle Forms often rely on DB-level security. Migration requires modern RBAC & SSO.

Approach:

• Integrated Azure AD / OAuth2.0 for single sign-on.

• Externalized RBAC in microservices using Spring Security + JWT.

• Implemented role-based menu rendering in Angular.

  
  

  KPIs Tracked

• % Business Rules Migrated & verified by SMEs

• % Test Automation Coverage for Angular UI & REST APIs

• Response Time (ms) for APIs vs. Oracle Forms benchmark

• User Adoption Rate post go-live

• Defect Leakage Rate during UAT/Production

11.Deployment & CI/CD

• Challenge:Earlier deployment was manual with Oracle Forms runtime; Angular + microservices required cloud-native DevOps.

• Solution:

  • Set up Azure DevOps pipelines for build, test, and deployment of Angular and Spring Boot apps.

  • Used Docker + Kubernetes (AKS) for containerized deployment.

  • Implemented blue-green deployments to minimize downtime.

12.Delivery Approach (Sample)

• Phase 1 – Discovery: Forms2XML extraction, rule cataloging, DB dependency mapping.

• Phase 2 – API & UI Design: Build microservices, design Angular components.

• Phase 3 – Iterative Migration: Migrate modules one by one, run dual-run comparison.

• Phase 4 – Hard Cutover: Switch users after full regression pass.

Outcome

✅ Delivered Angular-based responsive UI with 70-80% reusability of business logic through REST APIs.

✅ Reduced future change efforts by decoupling UI from backend.

✅ Improved performance by 20-30% due to optimized APIs and caching.

✅ Enhanced security via SSO, RBAC, and audit logging.

🏛 Modernized Architecture Flow (Oracle Forms ➝ Angular + Spring Boot + API Gateway)

[ User Browser ]
       │
       ▼
[ Angular Frontend (SPA) ]
 - Replaces Oracle Forms UI
 - Implements responsive UX
 - Uses Angular Reactive Forms for validation
 - Calls REST APIs (JSON)

       │ HTTP/HTTPS (REST API Calls)
       ▼
[ API Gateway (Azure API Management) ]
 - Single entry point for all APIs
 - Enforces security (OAuth2/JWT)
 - Rate limiting, throttling
 - Request/response transformation

       │
       ▼
[ Spring Boot Microservices (Modularized by Domain) ]
 - LoanService (loan origination, evaluation)
 - CustomerService (KYC, profile mgmt)
 - PaymentService (disbursement, repayment)
 - RuleService (centralized business rules engine)
 - NotificationService (email/SMS)
 - Integrated with Kafka for async events

       │
       ▼
[ Database Layer ]
 - Migrated from Oracle to Azure SQL / PostgreSQL
 - Schema refactored (normalized, modular)
 - Stored procedure logic converted to:
     - Microservice business logic
     - Drools / Decision Tables (for rules)
     - or REST-based rule engine

       │
       ▼
[ External Integrations ]
 - Credit Bureau API
 - Payment Gateway
 - Core Banking System
 - Fraud Detection Service

🔑 Key Points in Delivery

✅ UI Transformation

• Oracle Forms ➝ Angular SPA with reusable components.

• Converted UI triggers, validations to Angular reactive forms.

✅ Business Logic Migration

• Extracted PL/SQL logic from stored procedures.

• Refactored into Spring Boot services & REST APIs.

• Centralized rules using Drools or decision tables for maintainability.

✅ Security & Governance

• OAuth2 / Keycloak or Azure AD for SSO.

• Role-based access control (RBAC).

✅ CI/CD

• Automated build & deployment with Azure DevOps pipelines.

• Unit + Integration + Regression tests automated.

✅ Performance

• API Gateway caching + DB indexing to match Oracle Forms responsiveness.