Joe Fenton

Data and evals for AI // prev: founding team @inflectionai, PM @googledeepmind, VC at Invoke Capital and astrophysicist

[Joe Fenton @JoeFenton]

“All that matters for anyone in life is their family, their health and that’s always the same for everyone” — Mike Lynch

https://t.co/qxhJc7E66C

[Joe Fenton @JoeFenton]

https://t.co/L46Y3OduKY

[alphaXiv @askalphaxiv]

"MAI-Thinking-1: Building a Hill-Climbing Machine"

Microsoft just did something almost no frontier AI lab has done before

They shared how they engineered the data behind a frontier-scale model in unusual depth.

From data collection and eval decontamination, to data mix scaling, this paper lays out how they managed 30T pretraining tokens plus 3.55T midtraining tokens

Surprisingly, they also used no third-party distillation and no open-source training datasets

The model itself is not a jaw-dropping release, but the paper might be the best open look yet at a frontier-scale data factory and hill-climbing loop.

[Joe Fenton @JoeFenton]

Positive reaction to the mai-thinking-1 tech report is more than I imagined. Some nice write-ups from the open research community

[Joe Fenton @JoeFenton]

https://t.co/Nz1vqzrzEu

[Harveen Singh Chadha @HarveenChadha]

MAI-Thinking-1 by Microsoft looks to be approaching sonnet level model, the 109 page tech report is gold

they got 29T unique tokens without any synthetic tokens for pretraining which is exact opposite of what they were doing with phi models !!

so many counter intuitive decisions but the best part is they talk a lot about data.. this is a must must read

[Joe Fenton @JoeFenton]

https://t.co/TvEskMQDlh

[wh @nrehiew_]

Super detailed tech report for MAI-Thinking-1, with a ton of info on all stages of the pipeline. I'm surprised so much of this info is released :)

Super long thread on my notes:

[Joe Fenton @JoeFenton]

> buy truckloads of good books
> remove unspeakable amounts of slop from web data
> build a shedload of held-out evals
that was my work on mai-thinking-1

the model gets 97% AIME
and I can speak for hours about ISBNs

read the tech report: https://t.co/XyBJudWQE2

[Joe Fenton @JoeFenton]

@levelsio How’d you find Aman Tokyo?

[Joe Fenton @JoeFenton]

@IanOsband Tax slipped my mind somehow

[Joe Fenton @JoeFenton]

Anthropic achieves escape velocity - question is, who will be next...

[Joe Fenton @JoeFenton]

@_aidan_clark_ Nothing is more important than getting things done - decline meetings and lose the reports.

[Joe Fenton @JoeFenton]

Qualitatively observed the same among AI researchers. The most successful are often exceptionally strong in seemingly orthogonal areas.

Stay general kids…

[Joe Fenton @JoeFenton]

Wondering if OpenAI falls into this category…

[Joe Fenton @JoeFenton]

"Invest in companies that would be happy to see a 100x improvement in foundation models" -- paraphrasing Sam Altman

[Joe Fenton @JoeFenton]

This is going to be insanely popular

[Claude @claudeai]

Introducing Cowork: Claude Code for the rest of your work.

Cowork lets you complete non-technical tasks much like how developers use Claude Code.

[Joe Fenton @JoeFenton]

Build Jarvis with Claude Code, 100 lines of python and iMessage:
* Script watches Messages DB for texts from your number
* Forwards to Claude API with tools (shell, chrome, email)
* Claude executes + replies via iMessage
* Run as Launch Agent on always-on Mac

[Joe Fenton @JoeFenton]

2025 is peak “let’s ship a wrapped feature”