Strangler Fig Pattern

What problem does it solve?

This Skill helps engineering teams migrate large legacy systems safely by gradually replacing components around the host, avoiding risky big-bang rewrites and enabling continuous delivery of production changes.

Core Features & Use Cases

• Identify seams in the legacy code with clear input/output boundaries.
• Introduce an abstraction layer to route between old and new implementations.
• Implement the new version behind feature flags and run a phased rollout (dark launch, canary, ramp-up) with monitoring.
• Instrument safety checks and rollback criteria to ensure production stability during migration.

Quick Start

Start by identifying seams in the legacy system, add characterization tests, create an abstraction layer, implement the new version behind feature flags, and begin a staged rollout with monitoring.