René Dekkers

Every team has conventions that live in one person’s head and spread by code review. When you use Claude Code, that knowledge quietly forks: your setup knows your rules, nobody else’s does. Skills put the convention in the repo, so the whole team — and their AI — works the same way.

A lot of code is hard to test not because the business logic is complex, but because decisions and side effects are woven together. Functional Core, Imperative Shell is a simple rule for separating the two — and I pointed Claude Code at a tangled handler to do the split.

An order model with a status enum and a handful of nullable fields can represent far more states than are legal. I pointed Claude Code at one, had it count the illegal combinations, and let it redesign the type so they can’t be constructed at all.

One method returned a bool; another trusted that you’d called it first. That gap was the root of five separate problems. Here’s the refactor — parse, don’t validate — and how Claude Code did the mechanical work.

You get a feature request. Maybe a ticket, maybe just a Slack message. You open your IDE, create a branch, and start building. Claude Code writes the code, you review it, things move fast. Then, three hours in, you discover you’ve made five architectural decisions you never consciously made. The subscription entity is attached to the User because Claude assumed that. The tier check happens in the controller because that’s where it fit. There’s no audit trail because you never said you needed one. ...

Boris Cherny ships 10–30 pull requests a day and writes essentially zero lines of code by hand. That number spread across developer Twitter in January 2026, and since then I’ve watched teams respond in the worst possible way: spin up ten Claude sessions, produce ten times the chaos. The workflow matters. What makes it work is not the session count. Why this is worth your attention Cherny created Claude Code and leads it at Anthropic. Before that he was a Principal Engineer at Meta. He is not a productivity influencer who dabbled with AI for a week — he built the tool, uses it at extreme volume, and has been candid about what actually drives the numbers. ...

Eight days after publishing a guide to tuning Claude Code, a single week of releases — Claude Fable 5, a one-flag safe mode, Stop hooks that talk back, and guardrails that used to be your job — forced a re-tune. Here’s the delta, mapped onto the same layers, and what we changed in our .NET codebase.

Out of the box, Claude Code treats every repository the same. The difference between autocomplete and a coworker is configuration: layered memory, deterministic hooks, skills, MCP servers, and worktrees. Here’s how to build each layer — and how we applied it to a large .NET codebase.

No new model. Five orchestration features. And a roomful of engineers raising their hands when asked who had shipped a pull request that week written entirely by AI.

Event sourcing has always been a tough sell — powerful, but too much work for most teams. AI coding assistants change the cost side of that equation.