We all love to build greenfield projects, but the reality is that in most jobs you have to deal with a lot of legacy code. This doesn't mean the code is bad. It just means that choices were made that were the right ones at that time, or that the developers were not entire up-to-date with modern development practices. And that's exactly what this talk is about. I enjoy taking such a codebase and gradually introduce architectural seems, add a proper build pipeline, introduce temporary tests and then gradually refactor the codebase to combine more maintainable, testable and reliable. So in this talk, I'd like to unfold my extensive toolbox of practices, principles, tools and mindset to help you improve your legacy code without jeopardizing your business. Most of it will be .NET focused, but quite a few also cover JavaScript/TypeScript.

Covers topics like this

• Characteristics tests
• A proper IDE like Rider to
○ detect code inefficiencies and dead code
○ render project diagrams
○ Quickly navigate
• Editorconfig / eslint so auto-format works
• Nuke build pipeline to get consistency
• GitHub actions build
• Adopt a version strategy and name branches accordingly
• Adopt automatic versioning using Github
• Add API verification tests
• Functional folder structure
• Architecture slide
• Enable nullable types per file
• Reduce the scope of types and members to find more dead code
• Move new code to .NET Standard projects or cross-compile
• Switch to SDK-style csproj
• Add scripts or builds steps to run the code locally
• Pulumi to automate PR deployments
• Adopt structered logging
• Use Dependency Injection
• Introduce interfaces and delegates without going overboard
• Add architecture dependency frameworks
• C4 Model
• Use test containers