Mastering Harness Engineering

# 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 × Context × 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.)

At the request of our readers, we are issuing a 66% discount coupon for "Cognitive Load Management Techniques to Break Through the Limits of RAG Performance" (the 990,000 KRW course can be purchased for 330,000 KRW).

For your information, this course is currently in the process of posting the 2nd edition, which is a revision of the 1st edition.

In the case of the 2nd edition, all class materials have been posted, but the videos are still in the process of being uploaded.

I post the 2nd edition videos frequently, but it will take a long time (at least several months) to post all of them.

Please keep this in mind and carefully decide whether to use the coupon.

The deadline is the 19th and there is a limited number of coupons available, so please hurry if you need one.

You can download the coupon by entering the address below into your browser's search bar.

https://inf.run/QowXG