Computer Science PhD student @Columbia, NeuroAI Scholar @CSHL, data science @PwC

New York, NY
Todd Morrill retweeted
NEVER thought i would hear this from jeff dean he thinks we can compress chip design from 2 years to 3 months with RL + new EDA tooling essentially just by a specialized auto research loop for hardware!
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I’ve been tracking this work closely since I met @jeffreyseely at ICML, and it’s awesome to see this go live. I think there’s something so cool about that wave-like visual he produced showing how you can make predictive coding distribute its error signal about as well as backprop.
sharing a new paper! Augmented Lagrangian Predictive Coding I think one of the coolest unsolved problems is how the brain does credit assignment. thread 🧵
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I’ve been looking forward to a @BerenMillidge podcast for a while now!
New episode with @johnschulman2, @oneill_c and @BerenMillidge. I got together with some of the most insightful AI researchers I know who are at the openish companies, because I wanted to hear the details of what's actually happening at the frontier and what comes next. 0:00:00 – Steelmanning the case against RSI 0:18:39 – What’s driving the Chinese labs’ progress 0:28:06 – How will automated AI researchers be trained 0:33:51 – Will long-horizon RL elicit AGI? 0:45:24 – The sim-to-real gap 1:00:33 – How much progress is explained by data? 1:18:03 – Why is RL working so well? 1:24:54 – Move 37 and entropy collapse 1:28:31 – Rapid-fire timelines
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OK Claude Fable 5.1, I see you
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I just took a look at @CallosumAI's posts and announcements and it looks super impressive. Need to get the download from @achterbrain. They're attacking cost, accuracy, and/or speed of whatever workload you have by breaking it down into modular components and running those pieces on whatever hardware or model meets your specs. But I honestly think one of the coolest things that Callosum could do is serve as basically the OpenRouter for chips. Think about it—they don't need to be a chip company, which means they have no ultra-concentrated bet on some particular hardware that may not work out. At the same time, they could offer an invaluable resource to any hardware startup: an immediate sales channel. If it's as simple as changing an API call and pointing my workload at some new hyped chip, of course I'm going to give it a try. And the best part is that hardware designers can provide their specs, interface, etc., Callosum can plug the chip in and make it available, and coding agents will be able to help you get the most out of this new hardware, easing the adoption burden of new hardware. These guys are so well positioned for the Cambrian explosion of hardware heterogeneity we're about to witness over the next few years.
Today, we are sharing some of our advances in how we utilise heterogeneous compute to push the efficiency-frontier in cost, speed and performance for increasingly complex AI workloads. It starts with a simple observation: nearly every problem that requires intelligence can be decomposed into sub-parts. Once decomposed, heterogeneity becomes the natural path to greater capability, greater efficiency, and novel solutions.
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Absolutely enormous release of our SNN bullet trains codebase. For anyone tracking that work from ICML this year, you can now find the code here github.com/ToddMorrill/snn-b… Here's a bit of backstory on this work for anyone that's interested. This work started in summer 2024 when I interned with @TonyZador and @ChristianPehle at @CSHL. I knew practically nothing about SNNs. I had to build the system from the ground up to develop my understanding. I originally started working on decoders and synaptic delays, but I constantly found that simply running the event-based system was slow, resource intensive, and theoretically constrained which motivated the systems work—extreme parallelism and root solvers for flexibility of our design space. It turned out that the systems solutions we developed wound up being very valuable artifacts on their own. And another fun bit of history—this project started before Claude code was part of our workflow, which meant that all the JAX code you see is code that I largely wrote myself. Implementing speculative execution on a GPU, writing custom VJP functions to override some of JAX's bad memory management behavior, etc. pushed me to the absolute limit of my coding abilities. I think it forced me to grow and learn a lot.
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These agents are doing... chip design? 🤯 This is updating my mental model about how much of a moat you can put around a chip startup. I liked the idea of a chip startup because it was defensible compared to say, just an AI software-driven startup. AI startups have always struggled to maintain their edge because algorithms prove to be relatively easy to rediscover (we're watching this in real time at the highest levels as Chinese rivals catch up with OpenAI and Anthropic). Obviously, chip design isn't solved and a lot goes into this, but the trend is clear. We're probably going to see an explosion of hardware-software co-design innovation in the next few years. qwen.ai/blog?id=qwen3.8
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Happy @openreviewnet refresh day for @NeurIPSConf! Today's schedule: 1. look at a paper 2. check claude's progress 3. refresh OpenReview 4. repeat every 30 mins
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I'm really enjoying using Fable for coding, but it's still not great for technical writing. Frontier models in general seem to lack theory of mind for humans. They say both too much and too little. They tell you all the side quest technical details and jargon you've never heard of. At the same time, their arguments often skip key logical steps. For instance, I'm deriving the variational free energy/evidence lower bound in a paper and the model's first iteration wanted to emphasize that an entropy term was the differential entropy term (as opposed to the discrete entropy), which has no bearing on my optimization problem—details that don't matter, this is the "too much". At the same time, it jumped to the ELBO in basically one line, which would baffle anyone who's not an ace in probabilistic modeling—this the too little. Both the "too much" and "too little" lead to huge cognitive load and I think this is both worth measuring and trying to address in future model releases. And anecdotally, I hear from my collaborators, some of whom are medical doctors, that they face the same issue with tools like OpenEvidence—too much and too little information, leading to cognitive burden.
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That’s a wrap on @icmlconf for me. What a week—jimjilbang, Korean BBQ, posters, coffee chats, happy hours, vibes. So much to digest, and so hyped to push for @NeurIPSConf. These conferences are too fun
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We’re presenting Bullet Trains: Parallelizing Training of Temporally Precise Spiking Neural Networks @icmlconf this morning in Seoul, Korea at 10:30am KST at poster #408. Come by! And check out a summary of our work here: icml.cc/virtual/2026/poster/… @ChristianPehle @TonyZador
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Many of us love AI agents, like Hermes from @NousResearch, but you really have to scrutinize data privacy, because you're probably handing over some very personal data. Consider section 12.3 Your data. from the Nous subscription terms of service: portal.nousresearch.com/term…. It says "a. Nous Research may use Your Data for research, educational, analytical, and other similar purposes, including the development and improvement of artificial intelligence and machine learning models, algorithms, and related technologies. You hereby grant Nous Research a non-exclusive, worldwide, royalty-free, fully paid-up, transferable, and sublicensable license to use, reproduce, modify, create derivative works from, and otherwise process Your Data for the purposes of (i) providing, maintaining, and improving the Nous Research Services, (ii) developing new products, services, features, and technologies, (iii) training, fine-tuning, refining, grounding, evaluating, developing, operating, testing, and enhancing machine learning and artificial intelligence models, and (iv) generating aggregated, anonymized, or de-identified datasets and insights." That sounds about as bad as it gets. I raised a Github issue (github.com/NousResearch/herm…) to understand how I can enable zero-data retention and emailed support@nousresearch.com to see if this can be enabled and I'm not seeing a clear path forward. TLDR; tread carefully with a Nous portal subscription; host your own models, or use OpenRouter directly with the zero-data retention to ensure your data is being kept private.
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It was fun to participate in the Local Circuits Symposium at the Zuckerman Institute here @Columbia. I spoke about a predictive coding model augmented with a memory module that’s under development.
Is forgetting useful? This was among the deep questions about how memories are formed and used explored recently at Local Circuits, a symposium that brought together leading experts in biological brains and artificial intelligences from across @Columbia. Read more: zuckermaninstitute.columbia.…
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Need to memorize some material like a second language or ML foundations? I keep finding new use cases for local LLMs and in particular, my Hermes agent (@NousResearch). My latest thing is creating Anki flashcards based on old class notes (e.g., PDF docs) or online content (e.g., a blog post on PCA: peterbloem.nl/blog/pca). Kimi K2.6 (and many other multimodal models) can create beautiful flashcards with LaTeX and figures. Long story short, I enabled AnkiConnect (ankiweb.net/shared/info/2055…), which sets up a local webserver listening for card creation events. Then you can just point Hermes at the documentation for AnkiConnect (git.sr.ht/~foosoft/anki-conn…), the material for the flashcards, and let it rip. I iterated a couple of times to make sure the anki-flashcard SKILL.md file that gets created works reliably. But you can just imagine this being handy for turning Obsidian notes or really any source content into flashcards you can review every morning for 15 minutes. I know some are thinking, "making the flashcards is the learning" and yes, you're right. But that requires immense time. So if it's between not reviewing material (because I don't make cards) vs. actually reviewing material (because the LLM auto-generated the cards), then I'll take process that actually gets me to review things.
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Todd Morrill retweeted
Super happy that our work on faster training of SNN was accepted at ICML 2026! Exact backpropagation in spiking neural networks is hard in part because in contrast to state space models every spike introduces a sequential dependency. What if we could speculate and correct?
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Definitely some signal I was heading in the right direction with my little “chat with my Obsidian vault” project. My whole thing was privacy so the challenge was to see how good open source models are toddmorrill.github.io/self-o…
LLM Knowledge Bases Something I'm finding very useful recently: using LLMs to build personal knowledge bases for various topics of research interest. In this way, a large fraction of my recent token throughput is going less into manipulating code, and more into manipulating knowledge (stored as markdown and images). The latest LLMs are quite good at it. So: Data ingest: I index source documents (articles, papers, repos, datasets, images, etc.) into a raw/ directory, then I use an LLM to incrementally "compile" a wiki, which is just a collection of .md files in a directory structure. The wiki includes summaries of all the data in raw/, backlinks, and then it categorizes data into concepts, writes articles for them, and links them all. To convert web articles into .md files I like to use the Obsidian Web Clipper extension, and then I also use a hotkey to download all the related images to local so that my LLM can easily reference them. IDE: I use Obsidian as the IDE "frontend" where I can view the raw data, the the compiled wiki, and the derived visualizations. Important to note that the LLM writes and maintains all of the data of the wiki, I rarely touch it directly. I've played with a few Obsidian plugins to render and view data in other ways (e.g. Marp for slides). Q&A: Where things get interesting is that once your wiki is big enough (e.g. mine on some recent research is ~100 articles and ~400K words), you can ask your LLM agent all kinds of complex questions against the wiki, and it will go off, research the answers, etc. I thought I had to reach for fancy RAG, but the LLM has been pretty good about auto-maintaining index files and brief summaries of all the documents and it reads all the important related data fairly easily at this ~small scale. Output: Instead of getting answers in text/terminal, I like to have it render markdown files for me, or slide shows (Marp format), or matplotlib images, all of which I then view again in Obsidian. You can imagine many other visual output formats depending on the query. Often, I end up "filing" the outputs back into the wiki to enhance it for further queries. So my own explorations and queries always "add up" in the knowledge base. Linting: I've run some LLM "health checks" over the wiki to e.g. find inconsistent data, impute missing data (with web searchers), find interesting connections for new article candidates, etc., to incrementally clean up the wiki and enhance its overall data integrity. The LLMs are quite good at suggesting further questions to ask and look into. Extra tools: I find myself developing additional tools to process the data, e.g. I vibe coded a small and naive search engine over the wiki, which I both use directly (in a web ui), but more often I want to hand it off to an LLM via CLI as a tool for larger queries. Further explorations: As the repo grows, the natural desire is to also think about synthetic data generation + finetuning to have your LLM "know" the data in its weights instead of just context windows. TLDR: raw data from a given number of sources is collected, then compiled by an LLM into a .md wiki, then operated on by various CLIs by the LLM to do Q&A and to incrementally enhance the wiki, and all of it viewable in Obsidian. You rarely ever write or edit the wiki manually, it's the domain of the LLM. I think there is room here for an incredible new product instead of a hacky collection of scripts.
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Our new preprint on parallelizing training of temporally precise spiking neural networks is out! We show up to 44x speedups over a conventional sequential baseline. 1/N
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This also means memory and compute are proportional to the number of events, not the number of discrete time steps, which is critical for modeling long sequences. Not to mention the benefits of precise spike times, which enable us to explore richer neural codes. 6/N
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