# 21-breakincode.com — llms.txt

> William Hung's bilingual (English + Traditional Chinese) technical blog
> and portfolio. Senior Backend Engineer at Appier, building AI creative
> services, video pipelines, and reliability systems.

## Author

- Name: William Hung
- Role: Senior Backend Engineer at Appier
- Location: Taipei, Taiwan
- Expertise: Go, Python, TypeScript, AWS/Azure/GCP, Kubernetes, Docker, Terraform
- Certifications: AWS Solutions Architect Associate (SAA-C03)
- Education: M.S. Communication Engineering, National Central University (GPA 4.3/4.3)
- Also: B-boy since 2013, crew 21 BreakinCode

## Content Pillars

### Engineering
Backend systems, cloud infrastructure, DevOps, Go concurrency,
container orchestration, database internals, CI/CD patterns.

### Dancing (B-boying)
Physical training methodology, sports science applied to breaking,
mobility, energy systems, motor coordination.

### Others (Discipline / Personal Systems)
Atomic habits implementation, productivity systems, mental models,
learning methodology.

## Key Series (multi-part deep dives)

- Go OOM Debugging: 11-part series on diagnosing and fixing Go memory issues with Chrome sidecar
  /en/writing/from-19-goroutines-to-exit-137/
- JWT Security Audit: 7-part series on JWT attack surfaces and defenses
  /en/writing/algorithm-confusion-and-none-attack/
- B-boy Physical Training: 10-layer framework for breaking athleticism
  /en/writing/bboy-physical-training-ten-layers/
- Atomic Habits Applied: Book mapping + personal implementation cases
  /en/writing/atomic-habits-whole-book-map/
- Database Connections: Cross-engine query patterns and remote DB setup
  /en/writing/cross-engine-db-query/
- Image Processing: Crop, resize, fill lessons from production pipelines
  /en/writing/crop-resize-fill-four-image-processing-lessons/

## Languages

All content is published in both English and Traditional Chinese (zh-TW).
English: /en/
Chinese: /zh-TW/

## Links

- Site: https://21-breakincode.com
- LinkedIn: https://www.linkedin.com/in/chunwei-hung
- GitHub: https://github.com/21-BreakinCode
- Medium: https://medium.com/@william31525
- YouTube: https://www.youtube.com/@BreakinCode-wf8gp