.NET & C# Localisation
Organise RESX resources by feature area rather than putting all strings in one file. A Resources/Common.resx for shared labels, Resources/Auth.resx for authentication strings, and Resources/Checkout.resx for commerce flows is easier to maintain than a monolithic resource file. In ASP.NET Core, this maps directly to typed IStringLocalizer injection — IStringLocalizer of type Common resolves from Common.resx and its language-specific variants. Per-area organisation also allows translation assignments by feature without exposing unrelated strings to each translator.
Name resource keys using PascalCase to match .NET conventions and keep them semantic: Button_Submit is clearer than Label47. Avoid spaces, hyphens, and non-identifier characters in keys — the generated Designer.cs class exposes keys as properties, and non-identifier characters require workarounds. For strings containing positional format placeholders (zero-indexed curly brace arguments), write a resource comment documenting each argument's expected type and meaning so translators understand what each placeholder represents without seeing the calling code.
In ASP.NET Core, register localisation services in Program.cs with AddLocalization and configure RequestLocalizationMiddleware with your supported cultures and default culture. Use IStringLocalizer with typed generic parameters for compile-time satellite assembly binding and correct fallback chain resolution. In Blazor WebAssembly, satellite assemblies are loaded asynchronously at startup — configure lazy loading to download only the cultures your users actually need rather than bundling all satellite assemblies in the initial payload, which can be significant for applications supporting many languages.
Connect your GitHub, Bitbucket, or Azure Repos repository to Language Monster. Language Monster detects RESX files automatically, pulls changed strings from your base resource file, and pushes completed language-specific RESX files back to your repository ready for your MSBuild pipeline. .NET positional format specifiers are detected and protected during translation. XML data-type fields and comment nodes are preserved in the output files.
Enable build-time resource validation in your CI pipeline at the warnings-as-errors level to surface missing or mismatched keys before deployment. Language Monster's quality controls run spelling, grammar, and placeholder checks on every saved translation. Translation Memory carries forward work done in previous application versions — adding a new supported culture reuses the existing memory bank before any machine translation request is sent, reducing cost significantly for large, mature resource files.