Course Index for Busy People

What you learned, what to reach for, and where to find it

A single-page index of every technique covered in the course: what situation calls for it, the key tool, and direct links to the relevant code example, lecture slides, and docs.

When I… I use… So I can… Resources
Reactivity
have a costly filter used by multiple outputs @reactive.calc reuse one computation across dependent outputs, reducing redundancy app · L03 L04 · docs
need a side effect to run only when specific inputs change @reactive.event avoid unintended side effects from reactive cascades L03 · docs
need to trigger a reset or action on button click @reactive.event(input.btn) + @reactive.effect run DB writes or UI resets exactly when the user asks L03 · docs
Data I/O
want my app to react to users sorting/filtering/selecting rows DataGrid + .data_view() build logic on what the user sees app · L06a · docs
need to give users a data file (csv/…) @render.download + download_button let users take some results out of the app L06a · docs
need to save user input or logs across sessions external DB + @reactive.effect (with @reactive.event) store data in a way that survives multiple sessions and server restarts app-03 app-04 · L09 · docs
have a dataset too large to load at startup Parquet + DuckDB [+ ibis] keep the app fast without loading everything into memory app · L09 · ibis DuckDB
LLM & AI
want to embed a chat interface in my dashboard QueryChat let users explore data conversationally, in context app-07e app-07f · L07d · querychat
need to constrain what the LLM answers about system_prompt + data description focus the assistant on your data and prevent off-topic responses L07d · querychat
want the LLM to use instruments and tools chat.register_tool() (chatlas) extend the LLM with external functionality and data access L08a · chatlas
need structured fields from unstructured text Pydantic + structured output extract structured fields to use in code or output in a particular format L08b · pydantic
need the LLM to answer questions about my specific domain RAG (per-query injection) get correct answers without fine-tuning rag_demo · L08c · LlamaIndex
want to log what users ask the LLM on_tool_request hook + external DB audit trail without blocking the flow app-04 · L09 · querychat
want to measure if prompt changes improve output inspect_ai evals compare models and iterate with evidence L08e · inspect.ai
Geospatial
need to show geographic patterns Altair choropleth / point map explore regional variation interactively app-04 app-05 · L05a · Altair maps