# Lecture 19. Mastering Harness Engineering
## Notice on New Lesson Postings
Hello, students! For this course, **247** new lessons (totaling 34 sections) are scheduled to be posted sequentially. As I am producing multiple courses simultaneously, I am proceeding with a method of posting **a little bit of each course alternately**, rather than uploading one entire course at once. Please find the posting principles and the schedule for each section of this course below.
## Posting Principles
- Currently, I am rotating through a total of 19 courses in order (circular method), posting one lesson per course alternately.
- Postings are made on weekdays (Mon-Fri), with a total of 5 new lessons uploaded across all courses per day.
- For this course, the next lesson will be posted whenever its turn in the rotation comes around.
- The posting speed may feel slow compared to other courses, but all courses are progressing together in the same manner.
## Posting Schedule by Section (Total 34 Sections)
| Section | Number of Lessons | Start Date | End Date |
|---|---|---|---|
| Section 1. [Intro] What is Harness Engineering - The Three-Layer Structure and the World Outside the Model | 5 | 2026-07-06 | 2026-07-27 |
| Section 2. [Intro] The Ceiling of Prompts and Context - Why is a Harness Necessary? | 5 | 2026-07-31 | 2026-08-21 |
| Section 3. [Intro] The Topography of Harnesses - Agents, Workflows, and Orchestration | 5 | 2026-08-27 | 2026-09-17 |
| Section 4. [Intro] Setting up the Practice Environment and Minimal Harness Loop | 10 | 2026-09-23 | 2026-11-10 |
| Section 5. [Component 1] Control Flow - Loops, Branches, and Termination Conditions | 5 | 2026-11-16 | 2026-12-07 |
| Section 6. [Code Implementation Practice] Control Flow - Creating a Safe Agent Loop | 5 | 2026-12-11 | 2027-01-01 |
| Section 7. [Component 2] Tools - Schemas, Function Calling, and Tool Routing | 5 | 2027-01-07 | 2027-01-26 |
| Section 8. [Code Implementation Practice] Tools - Plugging Search and Calculation Tools into Agents | 5 | 2027-01-29 | 2027-02-17 |
| Section 9. [Component 3] State - Short-term/Long-term Memory and Checkpoints | 5 | 2027-02-22 | 2027-03-10 |
| Section 10. [Code Implementation Practice] State - Implementing Memory and Checkpoints | 5 | 2027-03-15 | 2027-03-30 |
| Section 11. [Component 4] Validation - Guardrails, Retries, and Self-Correction | 5 | 2027-04-02 | 2027-04-19 |
| Section 12. [Code Implementation Practice] Validation - Multi-layer Validation and Self-Correction Loops | 5 | 2027-04-22 | 2027-05-07 |
| Section 13. [Component 5] Hooks and Observability - Logging, Tracing, and Monitoring | 5 | 2027-05-12 | 2027-05-27 |
| Section 14. [Code Implementation Practice] Hooks and Observability - Tracing and Metric Pipelines | 5 | 2027-06-01 | 2027-06-15 |
| Section 15. [Component 6] Permissions and Safety - HITL, Sandboxes, and Approval Boundaries | 5 | 2027-06-18 | 2027-07-02 |
| Section 16. [Code Implementation Practice] Permissions and Safety - Approval Gates and Sandboxes | 5 | 2027-07-07 | 2027-07-21 |
| Section 17. [Pattern 1] Prompt Chaining - Breaking Big Tasks into Steps | 10 | 2027-07-23 | 2027-08-20 |
| Section 18. [Pattern 2] Routing - To the Path that Fits the Input | 10 | 2027-08-24 | 2027-09-17 |
| Section 19. [Pattern 3] Parallelization - Dividing and Voting | 10 | 2027-09-21 | 2027-10-15 |
| Section 20. [Pattern 4] Evaluator-Optimizer - The Loop of Generation and Critique | 10 | 2027-10-19 | 2027-11-12 |
| Section 21. [Pattern 5] Orchestrator-Worker - Dynamic Dividing and Merging | 9 | 2027-11-16 | 2027-12-07 |
| Section 22. [Pattern 6] Autonomous Agents - ReAct Loop | 9 | 2027-12-09 | 2027-12-29 |
| Section 23. [Multi-Agent 1] What is Multi-Agent - How it Differs from Single Agent | 10 | 2027-12-31 | 2028-01-20 |
| Section 24. [Multi-Agent 2] Collaboration Patterns - Manager, Handoff, and Debate | 9 | 2028-01-24 | 2028-02-09 |
| Section 25. [Multi-Agent 3] Implementation - Sub-agents and Context Isolation | 9 | 2028-02-11 | 2028-03-01 |
| Section 26. [Application 1] Coding Agent - The Loop of Writing, Executing, and Fixing | 9 | 2028-03-02 | 2028-03-20 |
| Section 27. [Application 2] Research Agent - Multi-Agent and Isolation | 8 | 2028-03-22 | 2028-04-04 |
| Section 28. [Application 3] RAG Harness - Converting Lecture 14 into a Harness | 9 | 2028-04-06 | 2028-04-21 |
| Section 29. [Application 4] Customer Support Workflow - Routing, Handoff, and HITL | 8 | 2028-04-24 | 2028-05-08 |
| Section 30. [Production 1] Reliability and Cost - Retries, Caching, and Optimization | 8 | 2028-05-10 | 2028-05-23 |
| Section 31. [Production 2] Evaluation - How to Measure Agents | 8 | 2028-05-25 | 2028-06-08 |
| Section 32. [Production 3] Debugging and Security - Tracing and Injection Defense | 8 | 2028-06-09 | 2028-12-15 |
| Section 33. [Three-Layer Integration 1] Prompt ร Context ร Harness | 9 | 2028-12-15 | 2028-12-19 |
| Section 34. [Capstone/Wrap-up] Comprehensive Project and Course Retrospective | 9 | 2028-12-19 | 2028-12-20 |
## Estimated Completion
Based on the current pace, the estimated completion date for all postings of this course is around **December 2028**. (The actual schedule may be moved forward or delayed depending on the production progress.)
