Learn RAG with Phoebe

Two tracks from "what is retrieval" to a RAG system you can trust

Retrieval-augmented generation is how you make an LLM answer from YOUR documents instead of guessing. A leader track teaches what RAG is, when it pays off, and how to judge one - no code. A builder track grows a real retrieval assistant across three escalating corpora: embeddings, chunking, a vector database, hybrid retrieval, reranking, grounding with citations, and evaluation. Taught from the official docs and short courses. Feeds straight into learn-langchain-with-phoebe.

2tracks
16sessions
3escalating corpora
45min per session

The leader track 🀝 · for C-level, managers & curious minds · 6 x 45 min · no code, ever

Thinking mode: what RAG actually is, when it beats fine-tuning, what it costs, how to judge whether a RAG system is trustworthy, and how to govern it - each session ends with questions to ask your data team.

The builder track πŸ› οΈ Β· for practitioners Β· 10 x 45 min Β· Python + a browser playground

One growing artifact: Recall, a retrieval assistant. Every session upgrades the same system - and every idea is felt in the in-browser playground first, so the vector database never gets to be magic.

πŸ”’ Builder 1 Β· easy

Embeddings 101

What a vector is, why cosine similarity ranks meaning, and why questions rarely share words with their answers. Live playground.

β–Ά Builders start here
βœ‚οΈ Builder 2 Β· easy

Chunking strategies

Fixed, recursive, semantic, sentence-window, parent-document - size and overlap, and why a bad chunk sinks good retrieval.

Recall indexes Corpus A
πŸ—„οΈ Builder 3 Β· medium

Vector databases

Chroma end to end - client, collection, add, query - then the pgvector and FAISS deltas, and HNSW vs IVF vs flat.

Recall gets a store
πŸ”Ž Builder 4 Β· medium

Retrieval basics

top-k similarity search, the retriever interface, and how to read a ranked result set with a critical eye.

Recall answers questions
🏷️ Builder 5 · hands-on

Metadata + hybrid retrieval

where-filters, temporal queries over dated incidents, and dense + sparse/BM25 hybrid with the alpha lever.

Recall reads Corpus B
🎚️ Builder 6 · hands-on

Reranking

Bi-encoder vs cross-encoder, retrieve-wide-then-rerank-narrow, MMR diversity, and query expansion / HyDE.

Recall gets precise
πŸ“Ž Builder 7 Β· hands-on

Grounding & citations

Answer only from context, cite the source, and the refuse-when-unknown guardrail that kills the confident wrong answer.

Recall reads Corpus C
πŸ”— Builder 8 Β· hardest

The full pipeline

Wire retrieve β†’ augment β†’ generate with the Claude API, and stream one cited, grounded answer end to end.

Recall ships v1
πŸ§ͺ Builder 9 Β· hardest

RAG evaluation

A golden set, faithfulness, answer relevancy, context precision and recall, hit-rate and MRR, and the LLM-as-judge.

Recall gets a scorecard
πŸš€ Builder 10 Β· hardest

Production RAG

Re-indexing and freshness, caching, the latency budget, monitoring, and cost - then the handoff to LangChain.

Recall graduates
easy - everyone medium hands-on / deciding hardest

The running project: three escalating corpora πŸ“š

The builder track grows one assistant, Recall, over the same three document sets - each harder to retrieve well than the last.

Corpus A Β· Personal

An MD's chief-of-staff notes

Emails, board notes, travel prefs. Pure semantic search: "what did I commit to in the Q2 board call?" Sessions b1-b4.

Corpus B Β· Product / Ops

Dated Jira incident tickets

Each ticket has a date and a severity. Now retrieval needs metadata and time: "what SEV1s happened in March?" Sessions b5-b6.

Corpus C Β· Company KB

A help-center for a support bot

Policy articles a customer bot answers from - grounded, cited, and willing to say "I don't know". Sessions b7-b10.

Choose your path πŸ—ΊοΈ

Two doors, one course. Leaders never see code; builders never sit through theory they have not first felt in the playground.

🀝 Leader (no code, ever) a1β†’ a2β†’ a3β†’ a4β†’ a5β†’ a6
πŸ› οΈ Builder (grow Recall) b1β†’ b2β†’ b3β†’ b4β†’ b5β†’ b6β†’ b7β†’ b8β†’ b9β†’ b10
🌱 Curious follower (a taste) a1β†’ a4β†’ b1
πŸš€ Full journey (lead AND build) a1-a6β†’ b1-b10β†’ LangChain β†—

The knowledge map 🧠

Both tracks at a glance - hover a session to spotlight its concepts, click any node to jump in.