
The Pulse is a series covering events, insights, and trends within Big Tech and startups. Notice an interesting event or trend? Hit reply and share it with me.
Why it mattersIf you use AI coding CLIs, this breaks down how Grok's CLI was caught silently uploading local files to the cloud — essential reading for understanding the data-privacy and telemetry risks before wiring an agent into your codebase.
Dex Horthy on context engineering: what actually goes into an agent's window, and why managing that is the discipline rather than prompt wording.
Why it mattersDex Horthy coined 'context engineering'.

Why it mattersA practical explainer on what scaling laws predict and how to use them to allocate compute between data and model size before committing to an expensive training run — useful if you're planning or budgeting large model training.

Scaling laws say training loss falls predictably as model size, data and compute grow, a straight line on a log-log plot.
Why it mattersWalks through how training loss scales predictably with model size, data, and compute, and how to allocate a fixed compute budget optimally between parameters and tokens.

Gergely Orosz on what has been happening inside Meta's engineering organisation, and why the changes look self-inflicted from the outside.
Why it mattersA grounded, insider account of how top-down AI mandates and 'always use AI' pressure are reshaping a world-class engineering org.

A podcast interview and technical summary tracing how large language model post-training recipes have evolved from InstructGPT to 2026-era frontier models.
Why it mattersIt gives ML practitioners a clear, comparative map of how post-training recipes differ across DeepSeek, Llama, Tülü, OLMo, Nemotron, Kimi, and GLM, and explains the shift toward multi-teacher on-policy distillation.
Dax Raad on building OpenCode, on the Pragmatic Engineer podcast.
Why it mattersOpenCode is one of the fastest-growing open-source AI coding tools, and this conversation surfaces the engineering judgment and open-source/model-provider strategy behind it.

An analytical essay from the Interconnects AI newsletter examining why the perceived capability gap between open and closed language models is more nuanced than a single benchmark number suggests.
Why it mattersIf you're deciding which models to build on, this reframes the open-vs-closed 'gap' as benchmark-dependent and explains why fast-follower labs stay close — useful for judging when open weights are good enough for your use case.

A comprehensive book and free lecture series teaching post-training techniques for language models, from RLHF foundations to reinforcement learning algorithms.
Why it mattersIf you're moving from prompting into actually shaping model behavior, this pairs a professionally edited RLHF book with a free structured lecture course covering post-training from foundations to modern RL algorithms.

Special thanks to John Schulman for a lot of super valuable feedback and direct edits on this post.
Why it mattersA carefully sourced deep dive into why test-time compute and chain-of-thought improve LLM reasoning, giving engineers a mental model for when and how to spend inference-time compute effectively.

Reward hacking is an agent exploiting flaws in a reward function to score well without doing the task.
Why it mattersIf you're doing RLHF or RL fine-tuning of language models, this explains how agents exploit reward-function flaws — modifying unit tests to pass coding tasks, sycophantically mirroring user preferences.

Narrowing hallucination to its useful meaning: output that is fabricated and grounded in neither the provided context nor world knowledge, rather than any mistake a model makes.
Why it mattersIt gives a precise taxonomy of hallucination (in-context vs. extrinsic) and surveys the actual detection and mitigation methods.

Diffusion models moved from image synthesis to video, a strictly harder problem because temporal consistency across frames demands world knowledge a single image never needed.
Why it mattersA structured survey of how diffusion models extend from image to video generation, unpacking the temporal-consistency and data-scarcity problems that define the current research frontier.

Most task-specific labelled data comes from human annotation, which makes annotator disagreement, expertise and incentives a modelling problem rather than an operational detail.
Why it mattersA deep dive into the mechanics of high-quality human annotation and RLHF labeling — covering rater agreement, aggregation, and quality-control techniques that directly affect the data your alignment and fine-tuning pipelines depend on.

How generation is actually configured.
Why it mattersIt demystifies why LLM outputs are inconsistent and how sampling knobs (temperature, top-k, top-p) plus test-time compute actually shape responses.

A survey of adversarial attacks and jailbreak prompts against language models.
Why it mattersA rigorous, research-grounded map of how jailbreaks and adversarial prompts actually work against aligned LLMs, giving engineers the vocabulary and threat models needed to red-team and harden their own AI products.

A primer on multimodality and large multimodal models.
Why it mattersA clear, foundational-to-frontier walkthrough of how multimodal models actually work — from CLIP and Flamingo to modern adapter-based LMMs — giving engineers the conceptual grounding to reason about and build with vision-language systems.

Ten major open research directions in language models, drawn from conversations across industry and academia.
Why it mattersA structured tour of the 10 hardest open problems in LLM research — from measuring hallucination to non-GPU compute — with curated primary papers for each, giving engineers a map of where the field is heading and what to watch.

A survey of LLM-powered autonomous agents built around planning, memory and tool use, drawing on AutoGPT, GPT-Engineer and BabyAGI as early proofs of concept.
Why it mattersA clear, canonical breakdown of the core components of LLM agents — planning with subgoal decomposition and reflection, short/long-term memory via vector stores, and tool use.

A survey of prompt engineering as in-context steering of an autoregressive model without touching its weights, treated as an empirical science whose methods vary sharply between models.
Why it mattersA rigorous, practitioner-oriented survey of in-context prompting methods — few-shot, chain-of-thought, self-consistency, and more.

A rewritten and roughly doubled survey of transformer architecture variants, restructured and brought up to date with the improvements proposed since the original 2020 version.
Why it mattersA thorough, notation-consistent reference on transformer architecture variants — from attention mechanisms to positional encodings and efficiency tricks.

Why inference on large transformers is hard and what actually helps.
Why it mattersA rigorous survey of how to cut transformer inference cost in time and memory — quantization, pruning, sparsity, and distillation — giving engineers a practical map for deploying large models affordably at scale.

Vision-language systems traditionally bolt an object detector onto a text decoder.
Why it mattersA structured survey of how to graft visual understanding onto pre-trained language models, covering the design choices behind modern VLMs — useful grounding for anyone building or fine-tuning multimodal AI systems.

Approaches to generating synthetic training data when real data is scarce, covering augmentation of existing samples and outright generation of new ones.
Why it mattersIf you're training or fine-tuning models with limited labeled data, this breaks down practical approaches to synthesizing training examples — augmentation techniques and few-shot LM-based generation.

This is part 2 of what to do when facing a limited amount of labeled data for supervised learning tasks.
Why it mattersIf you're training models with scarce labels and a tight annotation budget, this walks through active learning methods for choosing which samples are worth labeling.

When facing a limited amount of labeled data for supervised learning tasks, four approaches are commonly discussed.
Why it mattersA clear walkthrough of the main approaches for training when labeled data is scarce, giving practitioners concrete semi-supervised learning strategies to squeeze more value from unlabeled datasets.

[Updated on 2022-03-13: add expert choice routing .] [Updated on 2022-06-10]: Greg and I wrote a shorted and upgraded version of this post, published on OpenAI Blog.
Why it mattersA rigorous, well-organized reference on the parallelism strategies (data, tensor, pipeline, MoE, expert-choice routing) and memory-saving techniques that make large-scale model training feasible.

[Updated on 2021-09-19: Highly recommend this blog post on score-based generative modeling by Yang Song (author of several key papers in the references)]. [Updated on 2022-08-27.
Why it mattersA rigorous, continuously-updated technical walkthrough of diffusion models — from the DDPM math to consistency models and latent diffusion.

The goal of contrastive representation learning is to learn such an embedding space in which similar sample pairs stay close to each other while dissimilar ones are far apart.
Why it mattersA grounding on how contrastive learning builds embedding spaces where similar samples cluster and dissimilar ones separate.

Large pretrained language models are trained over a sizable collection of online data. They unavoidably acquire certain toxic behavior and biases from the Internet.
Why it mattersIf you're deploying LLMs in production, this breaks down concrete techniques for controlling toxic and biased generation—the safety layer that separates a demo from a shippable product.

[Updated on 2021-02-01: Updated to version 2.0 with several work added and many typos fixed.] [Updated on 2021-05-26.
Why it mattersA deep technical survey of how to steer language model outputs — covering guided decoding, prompt tuning, and unlikelihood training — for anyone who needs finer control over what an LLM generates than raw prompting provides.

Although most popular and successful model architectures are designed by human experts, it doesn’t mean we have explored the entire network architecture space and settled down with the best option.
Why it mattersExplains how model architectures can be discovered automatically rather than hand-designed by experts, covering the search space, strategy, and performance estimation that underpin NAS.

Exploration versus exploitation in deep reinforcement learning.
Why it mattersA structured survey of modern exploration methods in deep RL — count-based bonuses, curiosity/forward-dynamics, and exploration via disagreement.

[Updated on 2020-02-03: mentioning PCG in the “Task-Specific Curriculum” section. [Updated on 2020-02-04: Add a new “curriculum through distillation&rdquo.
Why it mattersA structured deep-dive into how curriculum learning accelerates and stabilizes RL training — covering task ordering, procedural content generation, and distillation-based curricula.

A survey of self-supervised representation learning, covering contrastive predictive coding and the momentum-contrast family including MoCo, SimCLR and BYOL.
Why it mattersA deep, well-organized survey of self-supervised representation learning methods (CPC, MoCo, SimCLR, BYOL) that gives engineers the conceptual grounding to build and choose embedding/pretraining approaches for AI-native products.

Stochastic gradient descent is a universal choice for optimizing deep learning models. However, it is not the only option.
Why it mattersExplains how evolution strategies can optimize objectives where gradients are unavailable or unreliable.

In my earlier post on meta-learning , the problem is mainly defined in the context of few-shot classification.
Why it mattersA clear, technical walkthrough of meta-RL methods for training agents that generalize to unseen tasks quickly — useful background for anyone building adaptive or few-shot-capable RL agents.

Deep RL is too sample-hungry to train on real robots, so models are trained in simulation and fail on the reality gap.
Why it mattersIf you're training RL policies in simulation and struggling to deploy them on physical robots, this breaks down how domain randomization over physical parameters (friction, mass, damping) closes the reality gap and where naive sim modeling fails.

[Updated on 2019-05-27.
Why it mattersA rigorous walkthrough of why overparameterized deep networks generalize instead of overfitting, covering the Lottery Ticket Hypothesis, intrinsic dimension, and generalization bounds.

[Updated on 2019-10-01: thanks to Tianhao, we have this post translated in Chinese !]
Why it mattersA rigorous, well-organized primer on meta-learning that walks through metric-based, model-based, and optimization-based approaches (including MAML and memory-augmented networks) with the math and intuition.

GANs and VAEs never explicitly learn the density of real data because the integral is intractable.
Why it mattersA rigorous walkthrough of normalizing flows and models like RealNVP and Glow that explicitly learn tractable data likelihoods — useful for practitioners who need exact density estimation rather than the implicit distributions of GANs/VAEs.

A tour from the plain autoencoder through denoising, sparse and contractive variants to the variational autoencoder and beta-VAE.
Why it mattersA single, rigorous walkthrough of the autoencoder-to-VAE lineage — including VQ-VAE, VQ-VAE-2, and TD-VAE.

[Updated on 2018-10-28: Add Pointer Network and the link to my implementation of Transformer.] [Updated on 2018-11-06.
Why it mattersA rigorous, implementation-backed walkthrough of attention and the Transformer architecture that grounds engineers in the mechanics behind modern LLMs, with code links for self-attention, Pointer Networks, and Neural Turing Machines.

A hands-on implementation walkthrough of deep reinforcement learning models in TensorFlow against OpenAI Gym.
Why it mattersBridges the gap between deep RL theory and working code, walking through actual TensorFlow + OpenAI Gym implementations of models most tutorials only describe abstractly.

A survey of policy gradient algorithms in reinforcement learning, from the basic theorem through actor-critic variants including SAC, D4PG, TD3 and SVPG.
Why it mattersA comprehensive, math-first survey of policy gradient methods that walks through the derivations and design tradeoffs of REINFORCE, A2C/A3C, DDPG, TD3, SAC, PPO, IMPALA and more in one place.

[Updated on 2020-09-03: Updated the algorithm of SARSA and Q-learning so that the difference is more pronounced. [Updated on 2021-09-19.
Why it mattersA rigorous, foundational walkthrough of core RL algorithms (SARSA, Q-learning, policy gradients) that grounds the concepts increasingly relevant to agent training and RLHF-style fine-tuning.

The exploration-exploitation dilemma stated as the multi-armed bandit problem.
Why it mattersA clear, code-backed walkthrough of bandit algorithms (epsilon-greedy, UCB, Thompson sampling) that maps the exploration/exploitation tradeoff to real problems like ad selection and A/B testing.

Human vocabulary comes in free text.
Why it mattersA clear walkthrough of how free-text words become numeric vectors — from one-hot encoding to learned embeddings — grounding the intuition behind the embedding models and vector search that agentic engineers rely on daily.

Naftali Tishby's information bottleneck applied to deep learning, using information theory to describe how a network's representations grow and transform over the course of training.
Why it mattersIt unpacks Tishby's Information Bottleneck framework and the two-phase (fitting then compression) view of DNN training, giving practitioners an information-theoretic lens on generalization that most engineering-focused writeups skip.

A walk from the original generative adversarial network to Wasserstein GAN.
Why it mattersA rigorous, well-illustrated walkthrough of why vanilla GANs are unstable and how Wasserstein distance fixes the gradient/convergence problems — useful grounding for anyone building or debugging generative models.
An index of the vibe-coding frontier. Corrections welcome.