
Staff engineer focused on agentic engineering and Developer Experience @datadoghq · Father to two small humans
Surrey, England
Joined October 2008
- Tweets1.6K
- Following93
- Followers208
- Likes787
Dottie, my main @bot helped me finally redesign my personal site
I'm not a designer and it won't win any awards, but after a lot of iterating and sharing inspiration with her I'm so happy with how it came out 🥰
Couldn't have done this on my own
fxndev.com
I'm a fan of the Hemingway bridge, stopping mid task so it’s easy to pick up tomorrow
But agents mess with this
Leaving them idle as I walk away feels wasteful but if I set them off I’ll keep thinking about next steps with out of date state
I need Hemingway Tasks 😅 something that sets up tomorrow better
Anyone have good ones?
“No model did best in its maker’s own harness” 🤔
Model Benchmarks Are Worthless
How can a model score 24% and 59% on the same 113 coding tasks?
It happens when you vary the harness that wraps it.
I’ve increasingly ignored most of the recent model leaderboard results. Partly from exhaustion and partly because improvements in a ranking don’t show up in the actual work.
So I asked the 8090 Labs team to measure what the leaderboards skip: the model and the harness together, on real bug fixes and features from open-source projects.
8090 Labs ran 7 models through 5 harnesses.
Here are a few results I didn't expect:
- Anthropic's Claude Fable 5.1 scored 41% in Claude Code and 61% in OpenAI's Codex. It made 28 tool calls at the median in one and 66 in the other.
- The cheapest runs weren't the cheapest work. GLM in Codex cost $0.22 a run and $0.93 per success. In Pi it cost $0.25 a run and $0.43 per success.
- GLM passed a task on both attempts 51 times in one harness and 16 times in another.
- GPT-5.6 Sol and Grok 4.6 barely cared which harness they were in.
The bottom line is that if you're picking a model/harness combo off a model-only leaderboard, you're making a critical decision based on only half the information.
8090.ai/blog/same-model-diff…
Is this rude?
I called my grok @bot Dottie
It felt like a good name to go with my Hermes agent Betty (who identifies as a friendly fox 🤷♂️)
🤖 Made with AI
I’ve been thinking about the different ways to use agents, how prompts change, and how trust is at the core.
Pairing → micromanaging → delegating
When pairing, you prompt very specifically: “Implement a function that reads from this table in the database; use columns xyz”
As trust increases, you move to micromanaging: “Let’s create a new endpoint for the API. Call it blah, and use JSON API spec like the other endpoints.”
Finally, when delegating: “Our users need to be able to …”
Does this fit? Curious what unlocked the next level of trust for you?










