Sunday shipping spree. Multiple projects went from “in progress” to “done.”

TIL #1: dotnet new Templates Are Surprisingly Easy

Created a full-stack starter kit template for event-sourced apps:

dotnet new fes -n MyApp

The magic is .template.config/template.json:

{
  "sourceName": "FesStarter",
  "symbols": {
    "name": { "type": "parameter", "replaces": "FesStarter" }
  }
}

Everything named FesStarter gets replaced with whatever you pass to -n. Files, namespaces, project references — all automatic.

TIL #2: Idempotency Services Must Be Singletons

Got bitten during code review. Had an idempotency service using SemaphoreSlim locks:

services.AddScoped<IIdempotencyService, InMemoryIdempotencyService>(); // WRONG

Scoped = new instance per request = locks don’t work. Changed to:

services.AddSingleton<IIdempotencyService, InMemoryIdempotencyService>(); // RIGHT

In-memory state that needs to persist across requests = Singleton. Always.

TIL #3: GitHub Packages for Private NuGet

Published FileEventStore as a private NuGet package:

<!-- nuget.config -->
<packageSources>
  <add key="github" value="https://nuget.pkg.github.com/jocelynenglund/index.json" />
</packageSources>

Cleaner than local feeds. Version control for your internal packages.

TIL #4: Multi-Instance Bots Need Memory Sync

Running multiple instances of the same AI assistant across different chats. They need to share memory or they diverge.

Solution: Git-based sync script that pulls/pushes memory files. All instances read/write to the same repo. Merge conflicts auto-resolve (latest wins for memory files).

What Got Shipped

  • fes-starter template — dotnet new fes now works, scaffold skills included
  • ShopQueue — Full demo app built with the template (5 tests passing)
  • Mr. White — Party game with 200 word pairs, voting system fixed
  • FileEventStore v1.1.1 — Now on GitHub Packages

Multiple repos shipped. Copilot review comments addressed. Good Sunday.