Advanced20 lessons
AI Research Scientist
Build the statistical, experimental, and model-level judgment needed to investigate new AI methods and defend empirical claims.
Aspiring research scientists and research engineers working on language models, training methods, evaluation, or interpretability.
You can frame a research question, design controlled experiments, reproduce model training, evaluate evidence, and diagnose what changed inside a model.
- 1Linear Algebra for MLFind hidden directions in a support-incident matrix with SVD, then use rank, PCA, truncation, and condition numbers without losing sight of what the numbers mean.Math & StatisticsEasy13 min
- 2Adam, Momentum, SchedulersTrace SGD, momentum, Adam, AdamW, schedules, and gradient clipping on one uneven loss surface. Learn what each optimizer buffer measures and how to validate a training choice.Math & StatisticsEasy15 min
- 3Probability for Machine LearningA beginner-first probability article that teaches events, priors, conditional probability, independence, Bayes rule, and base-rate mistakes through one API abuse-risk detector story.Math & StatisticsEasy19 min
- 4Statistics and UncertaintyEstimate abuse risk in a flagged review queue from finite labels, using bootstrap intuition, score intervals, sampling bias checks, and calibrated reporting.Math & StatisticsEasy12 min
- 5Distributions and SamplingModel an incident assistant with binary outcomes, request routes, tool-call counts, and tail latency, then challenge each simulation before trusting it.Math & StatisticsEasy12 min
- 6Hypothesis Tests, Intervals, and pass@kCompare a code-generation model with paired evidence, uncertainty for lift, and pass@k under a fixed sampling budget.Math & StatisticsEasy12 min
- 7Validation and LeakageMake model and policy claims honestly: define the decision moment, split access-review episodes by time and user, expose feature and preprocessing leakage, and audit LLM evaluation contamination.ML Algorithms & EvaluationMedium16 min
- 8Experiment Design and A/B TestingDesign a trustworthy online experiment for an AI support change: randomize customers, measure useful outcomes, quantify uncertainty, and reject false wins.ML Algorithms & EvaluationMedium20 min
- 9PyTorch Training LoopsBuild a PyTorch classifier from raw logits through autograd, validation, and reloadable checkpoints.ML Algorithms & EvaluationMedium18 min
- 10The Transformer Architecture End-to-EndTrace a support reply through masked attention, a decoder block, and next-token logits with readable NumPy and PyTorch code.Preparation & PrerequisitesEasy13 min
- 11Scaled Dot-Product AttentionLearn scaled dot-product attention from first principles, including Q/K/V routing, variance scaling, masks, multi-head shapes, KV-cache costs, and FlashAttention.Transformer Deep DivesHard41 min
- 12Scaling Laws & Compute-Optimal TrainingLearn the empirical power laws governing LLM performance, from Kaplan's parameter-heavy frontier through Chinchilla-optimal ratios to modern inference-aware training strategies.Advanced Training & AdaptationHard36 min
- 13Pre-training Data at ScaleUnderstand how web-scale pre-training data is extracted, filtered, deduplicated, mixed, tokenized, and packed into training-ready shards, including decontamination, late-stage annealing, and synthetic-data tradeoffs.Advanced Training & AdaptationHard37 min
- 14Build GPT from Scratch LabBuild and train a tiny GPT end to end on Shakespeare: tokenize with GPT-style subwords, remap active token IDs, run causal self-attention, track validation loss, save a checkpoint, and sample text.Advanced Training & AdaptationHard24 min
- 15Supervised Fine-Tuning PipelineRun supervised fine-tuning as a real training system: choose the learning objective before the update surface, verify response-token loss and packing, track the real batch budget, save resumable checkpoints, and export on held-out behavior.Advanced Training & AdaptationHard24 min
- 16Reward Modeling from Preference DataTrain reward models as a first-class post-training stage: validate chosen/rejected pairs and splits, fit a scalar reward head with Bradley-Terry loss, audit generalization, and decide when explicit rewards are worth the extra complexity.Advanced Training & AdaptationHard20 min
- 17LLM Benchmarks & LimitationsBuild an evaluation suite for a policy-answering LLM: score evidence use, understand public benchmark contracts, control judge bias, and make release decisions from private tests.Core LLM FoundationsMedium20 min
- 18Mechanistic InterpretabilityLearn how sparse autoencoders decompose transformer activations into candidate interpretable features, support circuit tracing, and enable controlled activation-steering experiments.Transformer Deep DivesHard30 min
- 19Reasoning & Test-Time ComputeUnderstand how reasoning models trade extra inference compute for better answers, and what that means for search, verifiers, KV cache pressure, and routing.Inference & Production ScaleHard43 min
- 20Recursive Language Models (RLM)Learn Recursive Language Models (RLMs): keep long context in a programmable environment, delegate targeted sub-calls, and release the design only after measured quality, cost, and safety checks.Advanced Training & AdaptationHard42 min