In an attempt to correct many perceived deficiencies in Entity Framework Core, Microsoft is introducing 40 breaking changes to EF Core 3. You can see the entire breaking changes list on Microsoft Docs, but here are some of the highlights. 

@NgModule({
  imports: [CommonModule, RouterModule],
  exports: [], // components that are used in app.component.ts will be listed here.
  declarations: [], // components that are used in app.component.ts will be listed here.
  providers: [BrowserStorageService, AppConfigService] // global singleton services of the whole app will be listed here.
})
export class CoreModule {
  constructor( @Optional() @SkipSelf() core: CoreModule) {
    if (core) {
      throw new Error("CoreModule should be imported ONLY in AppModule.");
    }
  }
};

@NgModule({
  imports: [CommonModule],
  declarations: [], // common and shared components/directives/pipes between more than one module and components will be listed here.
  exports: [CommonModule], // common and shared components/directives/pipes between more than one module and components will be listed here.
  /* No providers here! Since they’ll be already provided in AppModule. */
})
export class SharedModule {
  static forRoot(): ModuleWithProviders {
    // Forcing the whole app to use the returned providers from the AppModule only.
    return {
      ngModule: SharedModule,
      providers: [ /* All of your services here. It will hold the services needed by `itself`. */]
    };
  }
};

JavaScript idiosyncrasies, or things that are not easily understood 

In simple terms, before we write a line of code, we start each sprint planning session by outlining a blog post describing what our next release will be.

Razor Pages is a new feature of ASP.NET Core MVC that makes coding page-focused scenarios easier and more productive.

Razor Pages requires ASP.NET Core 2.0.0 or later. Tooling support for Razor Pages ships in Visual Studio 2017 Update 3 or later. 

VSCode for the C# Developer - Tim Corey - NDC London 2023

VSCode is a nimble editor that can do just about anything. In this session, we will set up and configure VSCode for use in C# development. Then we will use it to build, debug, and deploy a small .NET Core web application to Azure.
Along the way, we will go over a list of the top C#-focused plugins for VSCode. Whether you are just getting started with VSCode or you are used to VSCode but want to start building C# projects, this session will get you up to speed fast. 

“more than half of all new packages” on the official npm registry are just placeholders with READMEs that contain links to various nefarious sites.