Accenture (Avanade) · Case study
Enterprise Platform ModernisationLegacy transformation without stopping the business
Led the lifecycle transition of legacy enterprise systems into a modular platform — protecting revenue while unlocking AI capability.
PlatformArchitectureRoadmapLifecycle
20%
IT infrastructure & maintenance cost reduced
15%
Engineering productivity gain
Unlocked
AI capability on platform
Zero
Customer-visible disruption targeted
The problem
Monolithic legacy systems made every change expensive and risky. Release cycles stretched, AI capability was impossible to land, and technical debt was quietly becoming a commercial liability.
Discovery
Mapped change lead time and defect rate by module. A small number of modules accounted for the majority of delivery pain and blocked the highest-value roadmap items.
Customer research
- Stakeholder interviews across engineering, operations and commercial
- Cost-of-delay modelling for blocked roadmap items
- Customer impact analysis for each candidate migration path
Product strategy
Strangler-fig, value-first. Modernise the modules that unblock revenue and AI first; keep the legacy path live behind an abstraction until parity is proven. Never ask the customer to absorb the migration.
Prioritisation & tradeoffs
- Sequenced by (revenue unblocked + AI enablement) ÷ migration risk
- Explicit 'do not touch yet' list to protect focus
- Parity checklists as release gates instead of dates
Solution
- Modular service boundaries with versioned APIs
- Design system and component library for consistent UX across old and new
- Feature flags and dual-run for safe cutover
- Product architecture and roadmap communicated as a single living artefact
Architecture
- Abstraction/adapter layer fronting legacy and modern implementations
- Event-driven integration between modules
- Observability and rollback baked into every cutover
Execution
- Quarterly roadmap with migration milestones tied to customer-visible value
- Joint governance with architecture and delivery leadership
- Change management and enablement for internal teams
Lessons learned
- Modernisation only gets funded when it's expressed as revenue unblocked, not debt repaid.
- Dual-run costs money and buys sleep. Worth it.
- I'd define parity checklists earlier — ambiguity there is where timelines die.