ML Foundations
The math under the models — gradient descent, softmax, embeddings, similarity and ranking — taught as playable labs and runnable challenges.
AI System Designs 2
Design a RAG Pipeline
Build a retrieval-augmented generation pipeline step by step. See how documents are chunked and embedded, how a vector store answers semantic search, how two-stage retrieval with reranking finds the best passages, how the prompt is grounded to stop hallucination, and how evals keep a quietly-drifting index honest — through an interactive diagram that grows with each concept.
Design a Recommendation System
Build a large-scale recommendation system step by step. See how a two-stage retrieve-and-rank funnel picks the best few from millions, how two-tower embeddings and ANN generate candidates fast, how a heavy ranking model scores engagement, how a feature store stays consistent between training and serving, and how the feedback loop keeps recommendations fresh — through an interactive diagram that grows with each concept.
Coding Challenges 3
Softmax
The function at the end of every classifier and language model: turn raw scores (logits) into a probability distribution. Implement the numerically stable version so big logits do not overflow. Solve it in Python or TypeScript.
Cosine Similarity
The measure behind every embedding search and RAG system: how aligned are two vectors, ignoring their length? Dot product over the product of magnitudes — 1 identical, 0 orthogonal, -1 opposite. Solve it in Python or TypeScript.
Top-K Retrieval
The core of the "R" in RAG: given a query embedding and a set of document embeddings, return the indices of the k most similar docs by cosine similarity, with a stable tie-break. Solve it in Python or TypeScript.