the writer
Kim
Jangwook.
김장욱 · キム・ジャンウク · 金张旭
Renew day by day.
Hello, I am Kim Jangwook. jangwook.net is my personal technology blog for recording what I learn while building AI agents, automation, developer tools, and software products.
Content services such as Effloow and automation systems such as Agent Effi Flow live on separate domains. This site is the personal space where I keep experiments, implementation logs, and the reasoning behind technical decisions.
I write less like finished marketing copy and more like a working notebook: what I tried, what broke, and what I would do differently next time.
Careers
SPIKA Inc.
Bravance Technologies Inc.
Connecty Inc.
Portfolio
My Projects
Shadow Dash
Tech: Tauri v2, SvelteKit, PixiJS v8, Rust, TypeScript
One-touch platformer game traversing light and shadow. Day and night switch every 4 seconds - jump on shadows during day, on light during night. Coming to iOS.
Agent Effi Flow
Tech: SvelteKit, Supabase, Google Gemini API, Stripe
AI-powered B2B SaaS OCR automation system. Provides Receipt OCR for Tax Refund and Accounting OCR services targeting Japanese inbound tourism businesses and SME accounting teams.
Effloow
Tech: Paperclip, Codex, Markdown, GA4
A content-business experiment where AI agents handle planning, writing, and operational issues. It runs as a separate service at www.effloow.com, apart from this blog.
SSR Survey Analysis
Tech: Python, OpenAI API, LLM, Data Science
LLM-based Semantic Similarity Rating methodology for analyzing blog revisit intent. Conducted 225 evaluations with 15 diverse personas across 5 content categories, achieving ICC reliability of 0.833. Cost-efficient alternative to traditional surveys ($0.016 per evaluation vs $1-5).
Weather Information System
Tech: Svelte
A modern weather application built with Svelte framework, providing real-time meteorological data with a responsive user interface.
Let's Encrypt Domain Checker
A tool for checking and managing Let's Encrypt SSL certificates for domains.
Drone Information Hub
Comprehensive information resource about drones, regulations, and best practices.
Practical Libraries Collection
A curated collection of practical libraries and tools for professional development work.
Works
Invoice Management System
Tech: Laravel, Vue.js, AWS
An application created to assist freelancers with invoice management.
- Profile management
- Billing partner management
- Invoice management
Dashboard
Tech: Fuel PHP, Laravel, Vue.js, AWS
A comprehensive system that manages company employees, clients, man-hours, sales, and subcontracts with dashboard visualization.
- Internal information management
- Man-hour management
- Billing management
- Report management
Trial Lesson System
Tech: Fuel PHP, jQuery, AWS
A system that manages information on various trial lessons and classrooms, allowing follow-up status monitoring of students.
- Trial lesson and related information management
- Facility management
Member & Seminar Management System
Tech: Laravel, React, Marketo, AWS
A system that manages online and offline seminars and events held throughout Japan, with integration to marketing automation systems.
- Membership management
- Email management functions
- Seminar management
CDP (Customer Data Platform)
Tech: Python, Nuxt.js, GCP, AWS
A system that supports the construction of a data warehouse to store client data and enables website personalization.
EFO (Entry Form Optimization)
Tech: TypeScript, GCP
A service designed to reduce form-filling user stress and prevent abandonment through intelligent form-filling support.
comeet
Tech: Fuel PHP, Nuxt.js, AWS
A service that provides online sessions and lessons with modern web technologies.
REMO TAX: Tax-Free Digitalization
A tax-free procedure agency service for retail stores. Simplifies the complex duty-free process through smartphone-based operations.
- Simple processing: Staff only need to photograph passports and receipts
- Fast processing: Average 1-2 minutes per transaction
- Low cost: Initial fee of 10,780 yen, no monthly fees
- No specialized knowledge required