dotnet-modernize

Analyze existing .NET code for modernization opportunities. Identifies outdated target frameworks, deprecated packages, superseded API patterns, and missing modern best practices. Provides actionable recommendations for each finding.

Scope boundary: This skill flags opportunities only. For actual migration paths, polyfill strategies, multi-targeting guidance, and step-by-step version upgrade procedures, see [skill:dotnet-version-upgrade] and [skill:dotnet-multi-targeting].

Prerequisites: Run [skill:dotnet-version-detection] first to determine the current SDK, TFM, and language version. Run [skill:dotnet-project-analysis] to understand solution structure and dependencies.

Cross-references: [skill:dotnet-project-structure] for modern layout conventions, [skill:dotnet-add-analyzers] for analyzer-based detection of deprecated patterns, [skill:dotnet-scaffold-project] for the target state of a fully modernized project.

Modernization Checklist

Run through this checklist against the existing codebase. Each section identifies what to look for and what the modern replacement is.

1. Target Framework

Check <TargetFramework> in .csproj files (or Directory.Build.props):