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.
New essays this week
How to stop Cursor AI forgetting your .NET architecture (the $9 fix)
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.
How to use Cursor AI with Entity Framework Core (without blowing up your database)
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.
Cursor vs JetBrains Rider for C#/.NET in 2026: which to pay for
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.
6 daily senior rules
Rule 18: WebApplicationFactory for Integration Tests
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.
Rule 17: ConfigureAwait false in Libraries
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.
Rule 16: async void Outside Event Handlers
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.
Rule 15: Records for Value Objects, Classes for Entities
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.
Rule 14: Sealed By Default
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.
Rule 12: IOptionsSnapshot Over Raw Config
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.
Try one rule before you trust the whole kit
The free arch-core-lite.mdc 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.
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Free sample:
arch-core-lite.mdcon GitHub - Full kit (£19.99, one-time): Agentic Architect on Gumroad
- Daily rules feed: https://agenticstandardcontact-byte.github.io/agentic-architect/blog/
Canonical home for everything in this digest: https://agenticstandardcontact-byte.github.io/agentic-architect/blog/.