Every weekday a single, opinionated rule for senior C#/.NET engineers using Cursor. Here's the full week in one read — canonical posts live on the Agentic Architect blog.
Sat 30 May · .NET tooling
Cursor forgets your DI patterns, boundaries, and conventions every session. Here's a 4-rule framework that locks your architecture into the AI's long-term memory.
Sat 30 May · .NET tooling
Cursor AI generates N+1 queries, eager-loads entire databases, and skips AsNoTracking. Here's a rule-based guardrail system that catches 90% of EF Core mistakes before production.
Tue 26 May · .NET tooling
Senior .NET teams aren't picking - they're paying for both. The honest comparison, the pricing math, and the config that lets the two tools share state.
Sun 31 May
In-memory EF Core providers lie. Use WebApplicationFactory with Testcontainers (SQL Server, Postgres) for real integration coverage. Cursor defaults to UseInMemoryDatabase — it passes locally and ships the bug to production. Flag the in-memory provider in test projects.
Sat 30 May
Library code (non-ASP.NET) should ConfigureAwait false on every awaited Task. ASP.NET Core code should not. Cursor mixes the two contexts in the same solution. Detect the project type and enforce the right default.
Fri 29 May
async void is a deadlock and unhandled-exception trap everywhere except UI event handlers. The AI uses it routinely for "fire and forget" — wrong answer every time. Flag it on sight. Thu 28 May
Value objects (Money, Address, Coordinates) should be records. Entities with identity (Order, Customer) should be classes with an Id. Cursor mixes these constantly. A rule that classifies based on the presence or absence of an identity property keeps the distinction honest.
Wed 27 May
Mark every class sealed unless inheritance is explicitly planned. Stops Cursor inventing accidental inheritance hierarchies "for flexibility." Small but measurable virtual-call perf wins too.
Mon 25 May
Business code should never call IConfiguration directly. Strongly-typed IOptions or IOptionsSnapshot bindings only. The AI loves to "just grab the config value" — refuse it and force a settings class with validation attributes.
The free is one drop-in Cursor rule that ends the morning re-explanation ritual. Install in 60 seconds, see whether Cursor actually remembers your DI lifetimes, and decide for yourself whether the full kit is worth £19.99.
`arch-core-lite.mdc`
`arch-core-lite.mdc`
on GitHubCanonical home for everything in this digest: [https://agenticstandardcontact-byte.github.io/agentic-architect/blog/](https://agenticstandardcontact-byte.github.io/agentic-architect/blog/).