Does this skill support instant rollback?

Yes. Because the migration uses feature flags (FeatureResolverSingleton), you can instantly toggle traffic back to the legacy code path if any issues are detected in the new implementation.

How is behavioral parity ensured during migration?

The skill follows a TDD process where real JSON responses and performance baselines are captured from the live legacy endpoint and used as the 'Red' state for integration tests in the new API.

What is the Strangler Pattern in this context?

It is a design pattern used to incrementally migrate a legacy system by wrapping old endpoints with feature flags that route traffic to new services once they are ready, allowing for a gradual transition.

Is this skill specifically for .NET development?

While the provided templates and patterns focus on .NET Framework to .NET 6+ migrations, the methodology of strangling, feature flagging, and capture-based testing is applicable to most API modernization projects.

Strangler Pattern Legacy Migrator

Name: Strangler Pattern Legacy Migrator
Author: resolve-io

byresolve-io

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Desarrollo de API

Migrates legacy .NET controllers to modern Minimal APIs using feature-flagged routing and the Strangler Pattern for zero-downtime transitions.

The strangler-pattern skill provides a structured methodology for migrating legacy Express-Web-API controllers to a modern Actions.API architecture (MediatR-based Minimal APIs) without system downtime. It leverages feature flags for safe, per-tenant traffic routing, ensures identical behavior through a specialized capture-and-test TDD process, and utilizes lazy-loading patterns to maintain performance during the transition period. This skill is essential for complex, high-risk migrations where rollback capability and verified behavioral parity are critical requirements.

Características Principales

01Lazy-loaded service patterns to optimize performance during dual-stack operation

02MediatR and Minimal API pattern implementation for .NET 6+ targets

031 GitHub stars

04Feature-flagged traffic routing for controlled legacy-to-modern migration

05Capture-based TDD workflow ensuring 1:1 behavioral parity with legacy logic

06Standardized authentication bridging between legacy JWT and modern schemes

Casos de Uso

01Implementing safe production testing for rewritten business logic with instant rollback

02Gradually modernizing monolithic API endpoints using a systematic, per-endpoint approach

03Migrating high-traffic .NET Framework controllers to .NET 6+ with zero downtime

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add resolve-io/.prism strangler-pattern

For use in Claude.ai and ChatGPT

Download Skill