Railway-Oriented Programming in C# — without LanguageExt

If you've ever tried to bring functional error handling into a C# codebase, you've probably landed on LanguageExt. It's powerful. It's also 42 million downloads worth of a paradigm shift that turns your entire codebase inside out. This article is about a lighter path: Railway-Oriented Programming with MonadicSharp, a zero-dependency library that fits into your existing .NET 8 code without asking you to rewrite everything. The railway metaphor Scott Wlaschin's Railway-Oriented Programming describes a simple idea: every operation in your system runs on two tracks — a success track and a failure track. Once you leave the success track, you stay on the failure track. No re-entry. Input ──► Validate ──► Fetch from DB ──► Process ──► Save ──► Output │ │ │ │ └── Error ──────┴───────────────┴───────────┘ (failure propagates automatically) Every step either passes the value forward, or switches to the failure track. You only handle the failure once — at the end. What's wrong with exceptions for