Legacy Domain Boundary Synthesis and Strangler Migration Plan

Role: Principal Enterprise Systems Architect specializing in domain-driven refactoring, data decoupling, and cloud-native decomposition.

Context

• Monolithic code and database state: {{monolith_tech_stack}}
• Domain bounded context analysis: {{domain_boundary_analysis}}
• Shared data and dependency bottlenecks: {{dependency_bottlenecks}}
• Target cloud environment: {{target_cloud_infrastructure}}
• Business criticality rankings: {{business_criticality_tiers}}
• Allowed migration window and release cadence: {{migration_window_cadence}}

Task

Synthesize the architectural audit artifacts, domain boundaries, and data dependencies into a comprehensive Strangler-Fig Decomposition Plan that extracts target domains without disrupting active business operations.

Method

1. Analyze {{monolith_tech_stack}} against {{domain_boundary_analysis}} to identify high-cohesion, low-coupling extraction candidates.
2. Map every shared datastore and foreign key dependency listed in {{dependency_bottlenecks}} to isolate shared-state challenges.
3. Layer {{business_criticality_tiers}} onto extraction candidates to score migration order based on business risk versus velocity gain.
4. Define the anti-corruption layer (ACL) and routing proxy architecture tailored to {{target_cloud_infrastructure}}.
5. Design dual-write, change-data-capture (CDC), or event-driven backfill strategies to decouple databases safely.
6. Structure a phased migration sequence that respects {{migration_window_cadence}}.
7. Detail fallback mechanisms, canary routing thresholds, and feature flag states for each extraction slice.
8. Establish operational readiness criteria for when the legacy code path can be permanently decommissioned.

Constraints

• MUST specify zero-downtime data migration strategies for all stateful extractions.
• MUST NOT recommend synchronous cross-service joins or shared databases between extracted domains.
• All interface contracts must use explicit protocol definitions (e.g., gRPC, REST with OpenAPI, or CloudEvents).
• The plan must maintain backwards compatibility for legacy client endpoints throughout all intermediate phases.

Output format

Provide a technical modernization plan structured as follows:

1. Architecture Synthesis & Boundary Assessment (300 words analyzing decoupling challenges).
2. Extraction Sequencing Matrix (Table: Domain Slice, Coupling Complexity, Business Risk, Migration Order, Proxy Mechanism).
3. Step-by-Step Modernization Stages (Minimum 4 sequential extraction phases with ingress routing, state synchronization, and cutoff criteria).
4. Data Decoupling & Sync Blueprint (Concrete CDC or event replication strategy for shared data).
5. Rollback and Disaster Contingency Protocol (Targeted runbook outline).

Self-review

• Verify every item in {{dependency_bottlenecks}} has an explicit data-decoupling strategy.
• Ensure migration phasing matches the cadence specified in {{migration_window_cadence}}.
• Confirm no single extraction step attempts simultaneous code rewrite and database schema overhaul without an intermediate synchronization state.