Overheard from the Next Meeting Room: AI Is Everywhere Now
The conversations drifting from the meeting room next door have changed. AI isn't a novelty anymore — it's just how p...
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View All Posts →Selectively Stash Files with git stash push -m
How to stash only specific files using git stash push instead of stashing everything at once.
TypeScript Pick, Omit, Partial: Practical Utility Type Combinations
How to combine TypeScript utility types to create clean API request/response types without duplicating interfaces.
Extracting Generic Types with TypeScript infer Keyword
How to use TypeScript's infer keyword to extract types from generics cleanly.
Instant UI Updates with React useOptimistic Hook
Use React 19's useOptimistic hook to update the UI before the server responds.
CSS Container Queries: Component-Level Responsive Design
Use @container instead of media queries to make components responsive based on their parent size
TypeScript as const: Stop Type Widening for Good
Use as const to create type-safe constants without enums and prevent type widening
Promise.allSettled vs Promise.all: Handle Partial Failures Gracefully
When calling multiple APIs concurrently, one failure shouldn't take down everything
Generate UUIDs in Node.js Without the uuid Package
crypto.randomUUID() is built-in — no need for the uuid package anymore
TypeScript Enum vs Union Type: Which One Should You Use?
A practical comparison of TypeScript Enum and Union Type to help you choose the right one.
Next.js 15 Changed the Default Fetch Cache - How to Handle no-store
Next.js 15 changed fetch default caching to no-store. Here's how to fix the performance hit.
Serve Static Sites with Nginx + Docker
The simplest way to serve a static HTML/CSS/JS site using Nginx in a Docker container with Docker Compose.
I Asked AI to Build an App and It Was Done in a Day - But Store Registration Took 3 Days
Built an academy schedule management app in half a day with Claude Code. But getting it on both app stores took 3 days.
Cookie Authentication with localStorage Fallback
Migrate from localStorage to cookie-based auth while keeping backward compatibility for existing sessions.
Set Up a Monorepo with pnpm Workspace
Configure a monorepo with pnpm workspace to manage frontend, infra, and mobile projects in a single repository.
Next.js API Proxy with rewrites for Microservices
Use Next.js rewrites to proxy multiple backend microservices behind a single domain — no CORS headaches.
How to Properly Type React useRef with TypeScript
Whether you include null in the useRef generic changes the entire type. Here's how to get it right
Estimate LLM Token Count - Korean vs English Differences
A simple token estimation algorithm without a full tokenizer. Korean text consumes more tokens than English.
Type-Safe API Responses with TypeScript Generics
Stop using 'as' type assertions on every API call. Use generics to make your fetch wrapper truly type-safe.
Zod: Runtime Type Validation for TypeScript
TypeScript types vanish at runtime. Use Zod to validate API responses and external data at runtime
Build an FPS Monitor with requestAnimationFrame
Measure real-time FPS in web apps using requestAnimationFrame and detect performance degradation.
TypeScript satisfies Operator: Type Safety Without Losing Inference
Use satisfies instead of as to get both type validation and narrow type inference
React useEffect Infinite Loop: 3 Causes and How to Fix Them
Three common causes of useEffect running endlessly and the fix for each one.
Restructuring Jekyll Multilingual Blog URLs and Overhauling Pagination
The -en suffix on English post URLs was bugging me, so I restructured everything to /en/slug/. 140 files changed. The...
My $50 Credit Vanished in 3 Hours - The Real Cost of Claude Code 1M
The 1M context model is great, but... my $50 free credit disappeared in just 3 hours. The cost per query grows expone...
Escaping Compacting Hell - Claude Code 1M Context Model Review
Claude Code now offers 1M context models. The frustration of constantly watching for compacting messages is finally g...
AI Can Do Everything Now - So What Should We Build?
In an age where AI can build almost anything with a click, what should developers actually work on? A document editin...
CORS Error Complete Guide - From Cause to Next.js/Express Setup
When a CORS error shows up in your browser console, here's everything you need to fix it.
Auto-Deploy Docker Images to ECR with GitHub Actions
Set up a GitHub Actions workflow that automatically builds Docker images and pushes them to ECR on every push.
Python FastAPI + SQLAlchemy Async Database Connection Pattern
Set up async SQLAlchemy sessions in FastAPI with dependency injection for non-blocking database access.
AWS Lambda Deploy Script - Auto-Find CDK Function Names
Shell script pattern to automatically find CDK-generated Lambda function names and deploy code.
Everyone's Talking About OpenClaw, But I Was Already Building the Korean Version
Inspired by OpenClaw, I started building OKAIBOX - an AI agent optimized for the Korean environment. It starts with t...
Deep Copy in JavaScript with structuredClone
Stop using JSON.parse(JSON.stringify()). structuredClone is the native deep copy solution.
CSS :has() Selector: The Parent Selector We've Been Waiting For
Use the CSS :has() selector to style parent elements based on their children — no JavaScript needed.
Docker Volume vs Bind Mount: When to Use Which
Understanding the difference between Docker volumes and bind mounts, and when to use each.
I Asked AI to Design a 3D Hardware Case - It Took 5 Minutes
I was chatting with AI and asked for a 3D hardware case design. A complete model appeared in under 5 minutes. That wa...
Python match-case: Cleaner Alternative to if-elif Chains
Use Python 3.10's structural pattern matching to replace messy if-elif chains.
S3 Presigned URLs - Build One-Time Download Links
Combine S3 presigned URLs with DynamoDB TTL to create download links with expiration and download count limits.
JavaScript Temporal API - Finally a Proper Date Replacement
How to use the Temporal API to replace JavaScript's broken Date object with immutable, timezone-aware date handling
React useDeferredValue: Optimize Search Without Debounce
Keep input responsive while deferring expensive list rendering — no debounce needed
Why I Regret Paying for Annual AI Subscriptions
The AI market moves too fast. I paid for annual subscriptions and within months, better alternatives appeared. Here's...
Organizing CSS Priority with @layer
Use CSS @layer to take explicit control over cascade priority and end specificity wars.
Array Grouping in One Line with Object.groupBy
Stop writing reduce boilerplate for grouping arrays. Object.groupBy does it in one line.
Handling Fetch Timeouts with Node.js AbortController
A clean pattern for adding timeouts to fetch requests using AbortController in Node.js.
DynamoDB ConditionExpression for Concurrency Control
Prevent race conditions in DynamoDB using ConditionExpression for atomic conditional updates.
Offload CPU-Intensive Tasks with Node.js worker_threads
How to use Node.js worker_threads to run heavy computations without blocking the main event loop.
Reduce Selector Repetition with CSS :is() and :where()
How to use CSS :is() and :where() to eliminate repetitive selectors, and the key specificity difference between them.
Create Immutable Data Objects with Python dataclass(frozen=True)
Use Python's frozen dataclass to create immutable objects with built-in validation and hashability.
AWS CDK - Build a SES Email Lambda in Minutes
Set up a serverless email sending endpoint with AWS CDK: API Gateway + Lambda + SES.
I Tried Opencode... Turns Out Claude Code Already Does It All
I tried Opencode, a terminal-based AI coding tool. It's good, but Claude Code already had most of the features I needed.
What Services Should You Build in the AI Era - It All Comes Down to Data
AI can code, design, and even create presentations. So what should developers build? After much deliberation, my answ...
Vite Monorepo - Allow Parent Directory Access with server.fs.allow
Fix 'request url outside of Vite serving allow list' in monorepos using server.fs.allow.
Using __dirname in ES Modules - import.meta.url Approach
Get __dirname and __filename in ES Modules using import.meta.url and fileURLToPath.
Redis Key Naming Convention - Hierarchical Key Design
Organize Redis keys with a hierarchical naming convention and TypeScript helper functions.
Electron contextIsolation + Preload Security Pattern
Secure your Electron app by using contextIsolation and preload scripts to restrict renderer access to Node.js.
Node.js --expose-gc for Memory Leak Debugging
Use Node.js --expose-gc flag to trigger manual GC and identify real memory leaks.
S3 Cache Busting - Always Fetch the Latest File
Fix stale S3 config files caused by browser/CDN caching with three cache-busting techniques.
Prisma Index Strategy - Composite Indexes and Sort Direction
Configure single, composite, and directional indexes in Prisma schema to boost query performance.
Next.js Health Check API - Essential Production Monitoring Endpoint
Build a health check API endpoint in Next.js App Router with system metrics for production monitoring.
Node.js TCP Port Scanner - Using net.Socket with Timeout
Build an async TCP port scanner with Node.js net module — no external dependencies needed.
Node.js Get Local IP Address - Cross-Platform (Win/Mac/Linux)
Get the correct local IP address using os.networkInterfaces() across Windows, macOS, and Linux, excluding virtual ada...
Next.js HttpOnly Cookie JWT Auth - Protect Tokens from XSS
Store JWT in HttpOnly cookies instead of localStorage to protect tokens from XSS attacks in Next.js.
Docker Compose Redis Healthcheck - Guarantee Startup Order
Use healthcheck and depends_on condition to ensure Redis is fully ready before your app starts in Docker Compose.
Building a Kiosk with Raspberry Pi - More Pitfalls Than Expected
I built a store kiosk using a Raspberry Pi. As a web developer, hardware was a whole new world — and the unexpected p...
Auto-Inject Bearer Token with a fetch API Auth Helper
Stop repeating Authorization headers — build a fetch wrapper that auto-injects Bearer tokens.
Can One Person Really Develop Entire Projects? 200% AI Utilization with CDK + Lambda + Cursor
From the old days of creating separate repositories for each Lambda function to developing entire projects solo with ...
Creating Naver/Kakao OIDC for Firebase? Reality Hits Different
The story of pulling an all-nighter trying to add Naver/Kakao OIDC providers to Firebase
JavaScript Intl.NumberFormat - Format Numbers Without Libraries
Use the built-in Intl.NumberFormat API for currency, thousands separators, and percentage formatting without external...
Unity + Firebase Authentication Journey: From Anonymous to Account Linking
Seamless experience for both guests and members! From Firebase Anonymous Auth to Account Linking - real implementatio...
Building a GitHub Pages Tech Blog with AI - Complete Series Guide
From blog creation to multilingual support with Claude Desktop MCP - Complete guide to AI-powered tech blog construct...
Building a GitHub Pages Tech Blog with AI (5) - Completing Jekyll Multilingual Blog with MCP
Final stage of global tech blog completion from Jekyll multilingual system to entire series retrospective with MCP
Building a GitHub Pages Tech Blog with AI (4) - Perfect Implementation of Dark/Light Mode with MCP
Comprehensive guide to automatically building complete theme switching system from CSS variables to Giscus synchroniz...
Building a GitHub Pages Tech Blog with AI (3) - Setting up Giscus Comment System in 5 Minutes with MCP
Complete comment system setup from GitHub Issues configuration to Jekyll integration with single MCP command
Building a GitHub Pages Tech Blog with AI (2) - Complete Automation of SEO-Optimized Tech Posting with MCP
Revolutionary workflow where MCP automatically generates complete tech posts from idea to SEO metadata and images
Complete RAG Guide: Understanding True Data Integration AI through Manufacturing MES Systems
RAG is not just about VectorDB. Discover the true meaning of intelligent platforms that connect VectorDB + RDS + RawD...
AI Development Reality Check: Lessons from Blog Automation
Real stories from building a GitHub Pages blog with AI over the past few days. The light and shadow of AI development
Building a GitHub Pages Tech Blog with AI (1) - Creating Jekyll Blog Locally with Claude Desktop MCP
Revolutionary method to create complete Jekyll blog directly in local filesystem with MCP server without copy/paste
Automating Blog Image Generation with Vertex AI Imagen: From Python Package to MCP Server
Building a complete workflow for automatically generating images for blog posts using AI. From Python package develop...
vertex-ai-imagen: A Simple Python Package for Google Vertex AI Imagen
Introducing a Python package that makes it easier to use Google Vertex AI's Imagen image generation API. Start AI ima...
Easy MCP Installation Using Existing MCPs - Practical Guide for Installing Playwright MCP
Learn practical methods for Claude to automatically install new MCPs using already installed filesystem and desktop-c...
Building a Complete Tech Blog with Claude Desktop + MCP: The Reality of AI Pair Programming
I finally completed the tech blog I'd been postponing for years in just one day with Claude Desktop + MCP Server. Mar...
Getting Started with a Tech Blog Using GitHub Pages
Learn how to create your own tech blog using GitHub Pages and Jekyll with step-by-step instructions.
PM2 Cluster Mode for Next.js Production Performance
Use PM2 cluster mode to leverage multi-core CPUs and boost Next.js throughput in production.
Python Timestamp Guide - Current Time, Conversion, and Practical Usage
From getting timestamp values in Python to conversion methods and real project applications. Explained with ready-to-...
Node.js Redis Singleton Connection + Auto-Reconnect Strategy
Manage Redis connections as a singleton in Node.js with exponential backoff reconnection.
After 20 Years of Coding, AI Built My Website
For 20 years I typed every line of code myself. Now I tell AI what to build and a website appears. The feelings are.....
Docker Compose YAML Anchors (&) - Eliminate Repeated Config
Use YAML anchors (&) and merge keys (<<) in Docker Compose to eliminate duplicated service configurations.
How to Get Good Code From AI - It's Not Just About Prompts
Sloppy instructions produce sloppy code. But good prompts alone aren't enough — your project structure matters more t...
Cursor Agent After One Month - Where AI Coding Actually Stands
I used Cursor's AI agent mode in production work for a month. Productivity gains are real, but blind trust will burn ...
Docker Multi-Stage Build for Next.js - Optimize Image Size
Reduce Next.js Docker image from 1GB to under 200MB with a 3-stage Dockerfile.
Running LLMs Locally With Ollama - It Depends on the Use Case
I wanted to run LLMs locally so I set up Ollama. Surprisingly easy to get running, but the gap with cloud APIs is cle...
API Endpoint Security Without Authentication - How Far Should You Go?
Protecting API endpoints on public sites with no login system. CORS alone isn't enough, but you can't force authentic...
Next.js Prisma Singleton Pattern - Fix Hot Reload Connection Leaks
Fix Prisma client connection leaks during Next.js hot reload with a simple singleton pattern.
JavaScript UTC to KST Conversion - 3 Utility Functions for Production
Convert between UTC and Korean Standard Time (KST) in JavaScript without external libraries.
Vector Databases - Do You Actually Need One?
Building AI services, you hear 'you need a vector database' constantly. But do you really? Or can your existing datab...
Creating a Gnuboard Q&A Site Using ChatGPT-4o - Idea Journal
What if we create a Gnuboard-specific Q&A site using the trending generative AI technology? Let me organize my though...
Giving SvelteKit a Try - Am I Framework-Hopping Again?
I barely finished learning Vue.js and another framework caught my eye. SvelteKit claims to be faster without virtual ...
Linux SSH Key Generation - Complete ssh-keygen Guide
From SSH key generation to implementation! A complete guide to building secure server access environment with ssh-key...
Building an Automated Naver Blog Posting System with AWS Lambda + S3 + CloudWatch + SNS
A complete guide to building an automated Naver blog posting system using AWS serverless architecture, solving the co...
Hardware-Based Key Management and Access Control System Design Using Thingplug
IoT security system design based on Thingplug 2.0 platform - Implementing hybrid architecture with AWS Serverless and...
Using ChatGPT for Microservice Architecture Design - An Honest Review
I tried using ChatGPT to help design a microservice architecture. It's no replacement for an architect, but as a rubb...
Linux System Resource Monitoring with htop
Complete guide to real-time Linux system resource monitoring using htop. Efficient methods to analyze CPU, memory, an...
Building Remote Desktop with AWS EC2 - Reality and Future of Cloud Work Environment
Replace a $1,000 PC with AWS EC2 remote desktop for just $50/month! Real cost analysis and setup guide
The Blog Nomad Finally Settles Down
Naver Blog, Tistory, WordPress, GitHub Pages... After years of platform-hopping, I've finally settled. A developer's ...
Adding Specific Files from Ignored Directories in .gitignore
How to configure .gitignore to ignore directories while including specific files. Instantly solvable using ** patterns
Setting up SSH Push with Bitbucket Access Key
Complete setup guide for securely pushing to Bitbucket Private Repository using SSH Key without password authentication
Installing LEMP Stack on Ubuntu 18.04LTS: Complete Guide to Nginx, MariaDB, PHP 7.1
Complete guide to quickly installing LEMP stack on Ubuntu 18.04LTS. Solve everything from one-click scripts to multi-...
Complete Guide to Configuring MariaDB External Access
Step-by-step guide to configure MariaDB for external access by modifying bind-address settings and user permissions.
Setting up nginx Bandwidth Limiting - Complete limit_rate Guide
Complete guide on how to effectively limit bandwidth using limit_rate and limit_rate_after directives in nginx with p...
Complete Guide to GitKraken GitHub Organization Repository Integration
How to solve the issue of organization private repositories not showing in GitKraken through OAuth permission settings
Creating Photoshop Effects with CSS Blend Modes - Complete Guide to background-blend-mode and mix-blend-mode
Learn how to implement Photoshop blending effects using only CSS. Practical applications of background-blend-mode and...
Complete Guide to Gnuboard Hook Usage and Event Types
A comprehensive guide to using Gnuboard hook features for code injection without modifying the bbs folder, covering e...
JavaScript Number Padding with Zeros - Complete Guide to padStart() and Custom Functions
Learn all methods to pad numbers with zeros in JavaScript! From padStart() method to custom functions with ready-to-u...
Complete Guide to MySQL/MariaDB Database Backup and Restore via Console
How to backup and restore MySQL/MariaDB databases via console without GUI tools. Ready-to-use command collection for ...
Complete Guide to Fixing Chrome Yellow Autocomplete Bug - Experimental Features Reset & Korean Input Method Setup
How to completely resolve Chrome autocomplete duplicate input bug with experimental features reset and Korean input m...
Adding Values to HTTP Headers in JavaScript jQuery AJAX Communication
Learn core methods and practical examples for adding authentication tokens to HTTP headers using beforeSend and setRe...
ThemePress Addon Server Architecture - Microservice-Based Scalable Web Platform Design
Designing a scalable addon architecture for 100% free website streaming service. Infinite expansion with microservice...
Configuring Apache to Recognize PHP Code in HTML Files
Learn how to configure Apache web server to execute PHP code in files with .html extension through step-by-step instr...
Critical Mistake to Avoid When Integrating Amazon Cognito with JavaScript
Learn about the most common 'client secret' related error that occurs when integrating Amazon Cognito with JavaScript...
Complete Guide to Linux tar Command - Everything About Compression and Extraction
A comprehensive guide to the most commonly used tar command options and practical examples in Linux. Master compressi...
Fixing Korean Character Encoding Issues After Apache Server Migration
Learn about the causes of Korean character corruption after Apache server migration and how to resolve it through cha...
AWS Lightsail Revisited - It's a Completely Different Service Now
I tried Lightsail years ago and dropped it. Recently went back and it's transformed — affordable, capable, and actual...
Why Developer Communities Died - Or Did They Just Change Shape?
Developer forums used to be buzzing with activity. Now they're quiet. Did the communities die, or did they just evolv...
A jQuery Developer Picks Up Vue.js
After 10+ years of jQuery, I finally started learning Vue.js. Reactive data binding turns out to be a game changer.
Winning a Website Renewal Project Through Competitive Pitch
I won a website renewal project through a competitive pitch. Turns out writing proposals is harder than writing code.
API Gateway Stage-Specific Lambda Functions - A Tale of Debugging Permissions
I wanted API Gateway to call different Lambda functions per stage — dev, staging, prod. The docs made it look simple....
AWS Certified Developer Associate - Exam Review and How I Passed
I got hooked on AWS, studied for three months, and passed the Developer Associate exam. Here's how the prep went and ...
An On-Premise Developer Falls Hard for AWS
After 10+ years of physical servers in data centers, I finally dove into AWS. I thought I was late to the party, but ...
How My Parents' Generation Thinks About Retirement - A Developer Son's Worry
For my parents, owning a house IS their retirement plan. No pension strategy, no investments. And honestly, am I real...
MySQL uuid() in Practice - Stop Exposing Auto Increment PKs in URLs
Using auto_increment PKs directly in URLs gets flagged in every security audit. But replacing all PKs with UUIDs is w...
From On-Premise to Cloud - Confessions of a Developer Who Keeps Postponing Migration
New projects go to the cloud. Old ones stay on IDC servers. I keep telling myself I'll migrate them... but somehow ne...
When Coding Is Fun But Your Hands Won't Move - The Developer Laziness Trap
I still love coding, but my hands just won't move. The architecture is all planned out in my head, yet execution feel...
My Honest Review After Using Docker for Every Project for 2 Years
I switched every project to Docker two years ago. Low barrier to entry, easy deployments... but is it really all upside?