Module 4 · LLMs, Prompt Engineering & Context Engineering

Building with LLM APIs: lessons

Calling APIs, streaming, tool calling, caching, and keeping cost and latency under control in production.

4 lessons · 1h 6m

What this module teaches, what it asks of you first and how you practise it are on its syllabus page.

Your First API Call
16 min
One endpoint, one request shape: messages, roles and parameters — then streaming so the user is not staring at a blank screen.
Included with the track Simulation inside
Tool Calling
20 min
The model runs nothing: it asks, your code executes, and the result goes back. Understanding that division of labour is the whole of tool-calling safety.
Included with the track Simulation inside
Cost, Latency and Caching
16 min
An LLM bill is dominated by input tokens sent over and over. Prompt caching, a trimmed context, batching, and a model that is good enough — in that order.
Included with the track Simulation inside
Retries and Rate Limits
14 min
The API will slow down and occasionally fail. An app that survives knows which errors to retry, waits with backoff and jitter, limits concurrency, and has a fallback.
Included with the track Simulation inside

Your First API Call