Blog

Use Quartz.NET when an LLM job must run on a real cron and never overlap itself, Hangfire when each run must survive a restart and retry on rate limits, and a plain BackgroundService only for a loose in-process loop. A decision matrix with the cron and concurrency gotchas that pick for you.

The error means Data Protection lost the key that signed the token. Persist keys to a shared, durable store and call SetApplicationName so every instance reads the same key ring.

EF Core can't find a key for your type. Either name a property Id or {Type}Id, add [Key], call HasKey, or - if it is a view or raw SQL result - call HasNoKey.

.NET 11 Preview 5 adds a brand-new FullJoin operator to LINQ plus tuple-returning overloads for Join, LeftJoin, RightJoin, and GroupJoin that drop the result selector entirely.

Rule-based checks are your floor and they are non-negotiable; LLM-as-judge is the ceiling you add when code quality, not just correctness, is what you ship. Here is the decision, with cost, latency, and the SWE-bench gap that proves why.

Static server-rendered Blazor forms could only validate after a full POST round-trip. .NET 11 Preview 5 renders validation metadata so the Blazor JS enforces DataAnnotations rules in the browser, no circuit required.

Claude subagents give you orchestration-level parallelism out of the box: one agent spawns isolated sub-contexts that run concurrently. OpenAI Assistants never had that, and it shuts down August 26, 2026, so new parallel work belongs on the Responses API plus your own fan-out. Here is how the two models actually differ and which to reach for.

EnableRetryOnFailure conflicts with BeginTransaction. Wrap the whole transaction in db.Database.CreateExecutionStrategy().ExecuteAsync(...) so it retries as one unit.

.NET 11 Preview 5 adds JsonSerializer.SerializeAsyncEnumerable with topLevelValues: true, so System.Text.Json can now stream JSONL out, not just read it.

Claude Code v2.1.169 (June 8, 2026) ships a --safe-mode flag that disables every customization for clean troubleshooting, and a /cd command that moves your session to a new directory without breaking the prompt cache mid-run.