Johannes Wachter
Johannes Wachter
// HELLO

I’m Johannes Wachter

Sulu Core Developer and Symfony AI Core Team member. I build the AI tooling I write about, and turn what I learn into software you can actually understand, test, secure and maintain.

// FEATURED
// MEASUREMENT
Agents don't reuse what they can't discover →
September 08, 2026 · 8 min
A colleague's agent kept reinventing Symfony components that already existed. What shipped in response, and what a real benchmark found when the claim got tested.
// SHORTS
  • Somebody still has to read it

    A post proposing AI;DR hit #1 on Hacker News: if you didn't read and edit what the model produced, don't expect the author to read it either. Producing a wall of text became free.

  • How I Made Symfony's Maker Agentic

    Twelve merged pull requests in one release, my first-ever contribution to Symfony's maker-bundle. All of them were about the same thing: agents kept running into make:* commands that only worked with a human answering prompts, and simply crashed otherwise.

  • The idea nobody could place

    Coaching an innovation project this summer semester, one question had been sitting with me the whole time: whose idea was this, actually, and how much of it came from the model?

All shorts →

// LATEST
// ESSAY
The hardest code to delete is your own →
August 31, 2026 · 4 min
My first Symfony AI release as a core team member deletes the MCP server from Mate. PR #2380 ships in 0.13, and what it actually cost to ship the answer.
// MEASUREMENT
The Mate Lab: does an agent actually use a dev tool? →
August 25, 2026 · 6 min
I measured whether Symfony Mate actually gets used by a coding agent, not just whether it's available. The result behind the Kill the MCP bet.
// PERSONAL
Joining the Symfony AI Core Team →
August 13, 2026 · 3 min
Chris Hertel asked me to join the new Symfony AI Core Team alongside Fabien Potencier and Oskar Stark. What that actually means to me.
// EXPERIMENT
Kill the MCP →
August 04, 2026 · 10 min
I deleted the MCP server from a Mate prototype and kept the tools. What that cost, what it bought, and why the reflex is the thing worth killing.
// ESSAY
Vibe coding is no-code without a custodian →
July 28, 2026 · 9 min
Vibe coding can produce maintainable software. The harder question is who owns its dependencies, decisions and failures after launch.
// ESSAY
The wrong debate: what PHP taught me about agentic software →
July 22, 2026 · 8 min
MCP or CLI is the wrong fight. What PHP with Composer, PSR and Symfony already learned about building things together, one layer down.
// BUILD
The last mile: distributing Agent Skills to real agents →
July 09, 2026 · 9 min
The polyfill that bridges where the Agent Skills standard is heading and what agents can read today, and why distribution, not the protocol, was the real problem.
// BUILD
Skills over MCP: shipping Symfony know-how with Mate →
July 02, 2026 · 11 min
What an Agent Skill actually is, how you serve one over MCP, and lessons from building a reference implementation against a spec that kept moving.
// ESSAY
What happens to innovation when implementation becomes almost free? →
June 25, 2026 · 8 min
When code, design and content all get cheaper, maybe implementation was never the bottleneck. A note from the classroom on friction, the statistical mean, and where excellence shows up.
// BUILD
Giving AI assistants eyes →
June 18, 2026 · 6 min
Highlights from the Symfony Mate Q&A: the dev-only MCP server that lets AI assistants look inside your running app, and why better context beats more context.
// ESSAY
Why six people are enough and what coding agents have to do with it →
May 19, 2026 · 8 min
Six developers run Sulu, its enterprise projects and its cloud services. That only works because of ownership and context, and those are exactly what coding agents need too.

All writing →

Core Dev Sulu CMS · Core Team symfony/ai · Building Symfony Mate · External Lecturer @ FH Vorarlberg

More about me → Follow on LinkedIn

On the bad days, this is what I put on: Claude is in the Stand-up.