Enterprise Workflow & Integration Platform
Modernize a 15-year-old intranet platform serving 50K employees, enabling modern integrations while maintaining compatibility with 30+ legacy systems.
Business Context
Global financial services firm. Intranet was the nervous system—HR workflows, compliance tracking, document management, internal communications. Any downtime meant operational paralysis.
Scale & Constraints
50K daily active users, 30+ legacy integrations, zero-downtime migration requirement, strict security/compliance (SOX, GDPR), 15-year data migration.
Architectural Role
Enterprise architect for modernization program. Defined target architecture, integration patterns, security model, and phased migration roadmap.
System Design
Hybrid architecture: Modern API layer (microservices) fronting legacy systems via anti-corruption layer. Event-driven integration for real-time updates. Identity federation across legacy and modern systems. Headless CMS for content, React for presentation.
Key Architectural Decisions
- ✓Anti-corruption layer—isolated modern code from legacy complexity
- ✓API-first approach—enabled gradual frontend modernization
- ✓Event sourcing for audit-critical workflows—immutable history for compliance
- ✓Feature flags for migration—enabled gradual rollout per business unit
Trade-offs
- ⚠Kept some legacy systems running longer—migration risk reduction over speed
- ⚠Hybrid identity complexity—accepted for business continuity
- ⚠Higher latency on some legacy paths—preserved compatibility
Technologies
Measurable Outcomes
- →Zero-downtime migration across 18 months
- →80% of workflows modernized with maintained compatibility
- →50% reduction in integration maintenance effort
- →Full audit trail for compliance (100% SOX coverage)
Lessons Learned
"Legacy modernization is 20% technology, 80% change management. The architecture that works is the one that gets adopted. We spent significant effort on training, documentation, and building internal champions."