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.

Acerca de

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

Lazy-loaded service patterns to optimize performance during dual-stack operation
MediatR and Minimal API pattern implementation for .NET 6+ targets
1 GitHub stars
Feature-flagged traffic routing for controlled legacy-to-modern migration
Capture-based TDD workflow ensuring 1:1 behavioral parity with legacy logic
Standardized authentication bridging between legacy JWT and modern schemes

Casos de Uso

Implementing safe production testing for rewritten business logic with instant rollback
Gradually modernizing monolithic API endpoints using a systematic, per-endpoint approach
Migrating high-traffic .NET Framework controllers to .NET 6+ with zero downtime

Acerca de

Características Principales

Lazy-loaded service patterns to optimize performance during dual-stack operation
MediatR and Minimal API pattern implementation for .NET 6+ targets
1 GitHub stars
Feature-flagged traffic routing for controlled legacy-to-modern migration
Capture-based TDD workflow ensuring 1:1 behavioral parity with legacy logic
Standardized authentication bridging between legacy JWT and modern schemes

Casos de Uso

Implementing safe production testing for rewritten business logic with instant rollback
Gradually modernizing monolithic API endpoints using a systematic, per-endpoint approach
Migrating high-traffic .NET Framework controllers to .NET 6+ with zero downtime