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Independent Developer
AI × Software Development Notes
Practical insights on building products with AI, indie hacking, and software craftsmanship.
KeepOnFirst Journal
The context behind every product I build.
A working journal about AI-assisted development, indie products, and tools for focused work: what I built, why I built it, and what I decided to remove.
Built from practice and sources.
Technical notes document products, code, and development decisions. Research and everyday topics identify their sources and testing limits. Browse the topics below to find what you need.
Curated Topic Shelves
First-hand technical and product field notes across four core engineering domains.
AI-Assisted Dev & Agent Engineering
3 NotesWeb 3D, Three.js & Graphics
3 NotesIndie Products & Market Field Notes
3 NotesKnowledge Formats & Architecture
3 NotesKOF Guides · Knowledge Base
Guides Knowledge Base
Understand AI agents, WebGL, Three.js, and indie development terminology with working code examples.
Want to browse everything? Start with the article index.
Browse all 40+ journal articlesInteractive Labs
Validating architecture and algorithms with playable prototypes
Daily Challenge #—
Chinese Typing Daily Challenge
Everyone types the same passages today. 60 seconds, characters per minute, then the leaderboard.
Take the challenge3D Racing
Midnight Run: Xinyi Night Loop
Race a lap through a 3D night-time Xinyi district — right in the browser, nothing to install.
Start drivingInteractive Essay
The 3D Studio
An essay you can walk into — an immersive scroll-driven 3D storytelling experiment.
Step insideExperiments & Products
What I'm currently building or exploring.
iOSAIProductivity
Available on the App StoreKofAI Note
An AI second-brain note app. Share posts, articles, and YouTube talks in; AI turns them into searchable, chattable cards — and weeks later they actually come back.
iOSWidgetEducation
Available on the App StoreWidgetLearner
A vocabulary learning iOS app designed to live on your Home Screen. Learn new words effortlessly every time you unlock your phone—no app to open, no notifications. Just calm, passive, effective learning built into your day.
iOSProductivityUtility
Available on the App StoreKeepOnFirst Focus
A clean and easy-to-use Pomodoro focus timer. Even if you're new to the Pomodoro technique, you can get started right away and stay focused while working or studying.
- Landscape support for a more spacious view
- Ambient sounds to stay immersed
- Tags to label each focus session
iOSHealth & FitnessParenting
Available on the App StoreBabyDay
A baby activity tracker built for tired hands and busy days. Quick Add, voice input, and family sync—log in 3 seconds. Warm, gentle design that won't hurt your eyes at 3 AM.
WebGameEntertainment
Play NowSnake Game
Classic arcade game for quick breaks. Practice your focus and reaction time. No gambling, no pop-up interruptions, just pure fun.
WebGamePuzzle
Play NowBlock Puzzle
Timeless falling blocks puzzle. Test your spatial thinking and strategy. No gambling, no pop-up interruptions, just pure puzzle challenge.
WebToolTest
Try NowReaction Test
Test your reaction speed in milliseconds. Simple, accurate, and fun. Track your best time and improvement.
Let's Connect
Whether you have feedback on my apps, want to collaborate on an idea, or just want to say hi, I'd love to hear from you.