Quick Reference Guide
Jump to any lesson instantly!
🚀 Start Here
👉 New to backend? Start with Lesson 01: Project Overview 👉 Experienced dev? Jump to Lesson 06: Models 👉 Need specific topic? Use the index below
📖 Lesson Index — 36 Lessons Across 7 Modules
Module 1: Foundation (00, 01–05)
- 00 - Course Introduction
- 01 - Project Overview
- 02 - Backend Architecture
- 03 - Request Lifecycle
- 04 - Folder Structure
- 05 - Database Layer
Module 2: Data Layer (06–08)
Module 3: Services Deep Dive (08a–08e)
- 08a - OpenAI Service
- 08b - Monitoring Service
- 08c - Multi-Agent Email
- 08d - Document Service
- 08e - RAG Graph Service (LangGraph)
Module 4: API & Business Logic (09, 09a–09b, 10–13)
- 09 - API Routers Overview
- 09a - Agents Router Deep Dive
- 09b - Documents Router Deep Dive
- 10 - Dependency Injection
- 11 - Authentication
- 12 - Multi-Agent Workflows
- 13 - AI Agents
Module 5: Advanced AI Engineering (14–20)
- 14 - RAG Pipeline
- 15 - Embeddings
- 16 - Vector Databases & ChromaDB
- 17 - LangGraph & Corrective RAG
- 18 - Background Tasks
- 19 - Prompt Engineering & Tool Calling
- 20 - Memory & Context Management
Module 6: Production Mastery (21–27)
- 21 - Logging & Observability
- 22 - Exception Handling
- 23 - Testing
- 24 - Performance
- 25 - Security
- 26 - Caching
- 27 - Configuration & Environment Variables
Module 7: Integration & Flow (28)
Reference
- Exercises — 20 exercises, all grounded in this codebase
- Interview Questions — real, verifiable Q&A
- Glossary — every technical term
🔍 Find Topics Fast
Architecture & Design
→ Lesson 02: Backend Architecture
Database
→ Lesson 05: Database Layer → Lesson 06: Database Models
API Development
→ Lesson 09: API Routers Overview → Lesson 09a: Agents Router · Lesson 09b: Documents Router → Lesson 07: Pydantic Schemas
RAG, Embeddings, Vector Search
→ Lesson 14: RAG Pipeline · Lesson 15: Embeddings · Lesson 16: Vector Databases · Lesson 17: LangGraph & Corrective RAG
AI & LLMs
→ Lesson 13: AI Agents → Lesson 19: Prompt Engineering & Tool Calling → Lesson 08a: OpenAI Service
Security & Production
→ Lesson 11: Authentication → Lesson 25: Security → Lesson 22: Exception Handling → Lesson 23: Testing
Debugging
→ Lesson 03: Request Lifecycle
→ Lesson 28: Complete Backend Flow
→ Lesson 09a: the /stats endpoint bug
🎯 Learning Paths
Path 1: Complete Beginner (5–6 weeks)
Week 1: Lessons 00–05 · Week 2: Lessons 06–08, 08a–08e · Week 3: Lessons 09–13 · Week 4: Lessons 14–20 · Week 5: Lessons 21–27 · Week 6: Lesson 28, Exercises
Path 2: Experienced Developer (2 weeks)
Week 1: Lessons 01–02, 06–08e, 09–09b · Week 2: Lessons 14, 17, 22–27, 28
Path 3: Interview Prep (1 week)
Day 1–2: Lessons 01–02 (architecture) · Day 3–4: Lessons 06–07 (data models) · Day 5: Lessons 09, 13, 17 (APIs, agents, RAG) · Day 6: Lessons 22–25 (production) · Day 7: Interview Questions
💡 Quick Tips
Lost? Start with Lesson 01 Stuck on code? Check Lesson 04 Need a definition? See Glossary Interview tomorrow? Read Interview Questions
📚 Additional Resources
- Main README — Full course guide
- Exercises — practice against this exact codebase
- Interview Questions
- Glossary
36 lessons, verified against backend/app/ source. Last updated: 2026-07-18.