Member of Technical Staff @GoodfireAI working on AI interpretability for scientific discovery. Prev: @Harvard, neuroscience PhD @Columbia @cu_neurotheory

San Francisco, CA
Joined January 2015
Me: generate a novel 76-residue protein binder BoltzGen: best I can do is ubiquitin. I did a quick analysis of memorization in protein generations using @GoodfireAI’s Silico (now publicly available!). Silico makes it easier to investigate and debug model issues like this 🧵
Silico, the platform for ambitious AI research, is publicly available today. AI is advancing fast. The tools to understand it need to advance even faster. Silico lets you interpret and train your models at frontier scale. Learn more + get access 🧵
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The representations in protein language models contain lots of info about protein properties. With interp methods, we can extract that knowledge to predict if a protein variant is harmful and why! @jaanakprashar made a great tool demonstrating this application:
Replying to @GoodfireAI
By looking inside ESM-C, we can also predict *how* genetic variants affect a range of specific protein properties. These insights can help clinicians create new hypotheses for how to target and treat rare genetic diseases!
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Ching Fang retweeted
Silico, the platform for ambitious AI research, is publicly available today. AI is advancing fast. The tools to understand it need to advance even faster. Silico lets you interpret and train your models at frontier scale. Learn more + get access 🧵
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Ching Fang retweeted
This September, I will join the @FlatironInst Center for Computational Neuroscience as a Group Leader, where I will launch the High-Dimensional Dynamics & Computation Group. Info for postdocs and grad students is forthcoming. I am grateful to my mentors who made this possible!
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Ching Fang retweeted
BSF works for bio-models too! found this conservation manifold that looks like an octpus 🐙 in GPN-star, MSA based genomic foundational model
If models think in shapes, our tools should too. Our latest research: Block-Sparse Featurizers (BSFs), a new way to find concepts in model activations - using multidimensional “blocks” instead of single directions. (1/9)
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excited to see what BSFs will unlock for science models! early exploration finds subspaces that divide protein folds into subdomains. here's one in ESMC-6B showing a circle of subdomains within the ATP grasp fold
If models think in shapes, our tools should too. Our latest research: Block-Sparse Featurizers (BSFs), a new way to find concepts in model activations - using multidimensional “blocks” instead of single directions. (1/9)
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really cool example of what block sparse featurizers can do! 🧊
Replying to @GoodfireAI
We also revisited an interpretability classic: curve detectors in InceptionV1. Neurons and SAE features turn out to be fragments of one continuous orientation feature, and the block *also* contains higher-order Fourier harmonics that hadn’t been described before! (7/9)
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Ching Fang retweeted
If models think in shapes, our tools should too. Our latest research: Block-Sparse Featurizers (BSFs), a new way to find concepts in model activations - using multidimensional “blocks” instead of single directions. (1/9)
Neural networks might speak English, but they think in shapes. Understanding their rich *neural geometry* is key to understanding how they work – and to debugging and controlling them with precision. Starting today, we’re releasing a series of posts on this research agenda. 🧵
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You can discover manifolds with SAE features! Very excited about this line of work 🍩💿
The most popular way to interpret AI is missing the bigger picture. Models think in curved shapes. But sparse autoencoders (SAEs) work with straight lines. Can they still capture models’ curved neural geometry? Yes, but not how you might think! (1/7)
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Ching Fang retweeted
We achieved state-of-the-art performance in predicting which of 4.2 million genetic variants cause diseases by interpreting a genomics model, in a new preprint with @MayoClinic. We're now releasing an open source database for all variants in the NIH's clinvar database. 🧵(1/8)
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Ching Fang retweeted
We used interpretability to scale RL against open-ended tasks, cutting Gemma 12B’s hallucination rate in half by teaching it to self-correct in tandem with our probing harness.
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Ching Fang retweeted
We raised a $150M Series B at a $1.25B valuation to fundamentally change the field of AI. Scaling is powerful, but we can't intentionally design what we don't understand.
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🤖📊 NEW in the Deeper Learning blog: @AnnHuang42 & @KanakaRajanPhD break down their recent work examining how recurrent neural networks solve the same task in different ways —and why that matters. Joint work with @tweetsatpreet & @FlaviohMar bit.ly/4kj4fVd #NeuroAI #AI
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A really exciting example of using interp to advance scientific progress! I had a lot of fun working on this with our scientific discovery team :)
We've identified a novel class of biomarkers for Alzheimer's detection - using interpretability - with @PrimaMente. How we did it, and how interpretability can power scientific discovery in the age of digital biology: (1/6)
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Kimi is just like me frfr Steering @Kimi_Moonshot's K2 Thinking's reasoning in the Kimi CLI
Our infra lets us steer trillion-parameter frontier models in real time: - live, mid-CoT edits to internal activations - directly altering how the model reasons (not just outputs) - stackable edits - no added latency We can make models more Gen Z, more concise, etc.
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Ching Fang retweeted
Our infra lets us steer trillion-parameter frontier models in real time: - live, mid-CoT edits to internal activations - directly altering how the model reasons (not just outputs) - stackable edits - no added latency We can make models more Gen Z, more concise, etc.
Replying to @gopalkraman
at @GoodfireAI, @RyanPanwar and Michael Anderson are building tools to intentionally design and control AI, moving beyond prompting to direct, real-time intervention.
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🔴 Live: Panel discussion #1: @ MAIN2025 The future of Neuroscience - The role of AI ?  with Andreas Tolias, Siva Reddy, Joao Sacramento, Ching Fang + Eva Portelance Moderated by Patrick Mineault @patrickmineault #MAIN2025
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Had a great time at MAIN 2025! Loved chatting with everyone 😊
🎉MAIN 2025 conferences just kicked of Our opening lecture is by Ching Fang (Goodfire AI, San Francisco) - "From Memories to Maps: Mechanisms of In-Context Reinforcement Learning in Transformers" Montreal AI & Neuroscience is brought to you by @ai_unique #MAIN2025 #NeuroAI #RL
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I'll be presenting this as a spotlight work at the #NeurIPS2025 mechanistic interpretability workshop this Sunday in the afternoon session!
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One caveat is that we used SFT on the base model's own responses, which might preserve more of the original activation space. There's room for more testbeds here - RL-induced encoding, more complex ciphers, etc.
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But overall this is encouraging for interpretability - simple mechanistic tools may be more robust to encoded reasoning than we expected. Joint work with Sam Marks @saprmarks, done during my fellowship with Cambridge Boston Alignment Initiative @cbai_ai
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