Blog & Guides
Long-form Korean-law / tax / seller / lifestyle guides that sit behind each tool. All posts are bilingual (KR / EN).
Blog · 2026-05-09
01Build notes — search bar, card priority, AdSense review prep (2026-05-09)
A single-day build log: home search bar, data-driven card priority, and AdSense review-prep code changes — with rationale and snippets.
- Build log
- Search
- AdSense
Blog · 2026-05-08
02Self-interview — why micro-tools instead of a "real" SaaS
A solo developer interviews himself on five topics — day job, side projects, family, money, and burnout.
- Self-interview
- Solo developer
- Honest
Blog · 2026-05-07
03Korean Micro-SaaS Search Trends — 5-Year Analysis (2021–2026)
Five years of Korean search interest in "micro-SaaS", "solo developer", and "side project" — using Naver Datalab and Google Trends.
- Search trends
- Data analysis
- 5-year
Blog · 2026-05-05
0412 questions readers keep asking (Spring 2026)
Twelve questions that keep showing up in mail, DMs, and Threads — answered as honestly as I can.
- FAQ
- Q&A
- Reader questions
Blog · 2026-05-03
05Solo, 119 micro-sites, 1 year — an honest retrospective
What went better than expected, the surprises, the broken builds, and family time — a first-person look back at one year solo.
- Retrospective
- Solo
- Operations
Blog · 2026-04-27
06Building 100+ Micro-SaaS Tools — Operational Lessons (2026 Retrospective)
A solo operator running 119 micro-SaaS tools shares lessons on infra, SEO, AEO, and operations — including the most expensive mistakes and the highest-leverage moves.
- Micro-SaaS
- Retrospective
- Infrastructure
Blog · 2026-04-27
07MapleStory EXP Booster ROI — Is It Actually Worth It? (2026)
A data-driven breakdown of 11 MapleStory EXP boosters — including cash, events, and guild — by EXP/hour, KRW/hour-equivalent, and time-to-cap.
- MapleStory
- EXP
- Gaming
Guide · 2026-04-27
08Infant Development Milestones Checklist (0–36 Months, 2026)
0–36 month milestones across motor, language, cognitive, and social development per CDC and the 2025 Korean Pediatric Society — plus when to seek a consult.
- Development
- Milestones
- Parenting
Guide · 2026-04-27
09Korean Baby Food (Iyusik) — Stage-by-Stage Start Guide (2026)
A one-page reference for Korean baby-food stages — early / mid / late / completion — with foods, allergens, and timing per the 2025 Korean Pediatric Society guidance.
- Baby food
- Infant
- Parenting
Guide · 2026-04-27
10Korean Food-Delivery Platforms — Fee Comparison 2026 (Baemin / Coupang Eats / Yogiyo)
Baemin 9.8% / Coupang Eats 9.8% / Yogiyo 12.5% — fee schedules, delivery-cost burden, and ad cost compared across the three Korean platforms.
- Delivery
- Baemin
- Coupang Eats
Guide · 2026-04-27
11Coupang vs Naver SmartStore — Where Should Korean Sellers Launch? (2026)
Comparing Coupang and SmartStore on 4 axes — category, SKU type, capital, and logistics — with a launch-platform recommendation for 90% of new sellers.
- Coupang
- SmartStore
- Seller
Blog · 2026-04-27
12FX "Scams" vs Real Cost Differences — Card vs Cash vs Transfer (2026)
Putting the "exchange booth scam" myth under data. The legitimate cost gap is 0.5–5% across card/cash/transfer; only above 5% is actual fraud.
- FX
- Card payment
- Transfer
Guide · 2026-04-27
13Korean Cross-Border Customs ₩200 / $150 Threshold — Full Guide (2026)
US $200 / others $150 duty-free threshold for Korean personal imports — including bundling rules, customs codes, and refund procedure on returns.
- Cross-border
- Customs
- FTA
Blog · 2026-04-27
14Pet Age in Human Years — The Correct Formula (2026)
The "dog × 7" formula is wrong. Here is the 2026 correct conversion by breed size and species, plus stage-by-stage care notes.
- Pet age
- Dog years
- Cat years
Guide · 2026-04-27
155 Legal Ways to Save on Korean Car Tax (2026)
Annual prepay, EV exemption, light-car cap, timing split, and vehicle swap — five legal ways to cut Korean car tax in 2026.
- Car tax
- Annual prepay
- EV
Blog · 2026-04-27
16BMI vs Body-Fat Percentage — Which One Actually Matters? (2026)
Why high muscle mass makes BMI mislabel you as overweight, and the case for tracking body-fat percentage, waist, and visceral fat together.
- BMI
- Body fat
- Health
Blog · 2026-04-27
175 Ways to Save on FX — Real Tactics for Travel & Cross-Border Shopping (2026)
Card vs cash vs exchange booth vs Travel Wallet, plus intraday FX patterns — five tactics that can save ₩300K–500K on a $10K spend.
- FX
- Travel
- Cross-border shopping
Guide · 2026-04-27
18What Is llms.txt and Why You Need It — AEO Primer (2026)
In the AI-search (AEO) era, llms.txt helps LLMs cite your site correctly. This primer covers how to write it and how it differs from robots.txt / sitemap.xml.
- llms.txt
- AEO
- AI search
Blog · 2026-04-27
195 Ways to Convert HEIC to JPG — Compared (2026)
Five ways to convert iPhone HEIC to JPG — browser, iPhone setting, macOS Preview, Windows app, and CLI — compared on quality, EXIF, and speed.
- HEIC
- Image conversion
- iPhone
Guide · 2026-04-27
20Korean Home Pension vs National Pension vs Private Pension — 2026 Comparison
A side-by-side table of the three Korean pensions plus four asset-mix strategies showing how to combine them by net-worth profile.
- Pension
- Home pension
- Korean retirement
Guide · 2026-04-27
21Korean FIRE — Is It Actually Feasible? (2026)
Re-deriving the 4% rule for Korean tax, inflation, and pension realities — ₩1.2B needed at ₩48M annual spend, with 4 realistic accumulation scenarios.
- FIRE
- Retirement
- Financial planning
Guide · 2026-04-27
22Korean Gift Cash for Weddings & Funerals — Amount Guide by Relationship (2026)
Coworker ₩50K, friend ₩70–100K, relative ₩100–200K — the 2026 reference for Korean wedding/funeral cash gifts, adjusted for meal-cost inflation.
- Wedding gift
- Funeral gift
- Korean etiquette
Guide · 2026-04-27
23Korean Wedding Budget — 2026 Average Costs and Allocation Playbook
Average Korean wedding cost is ₩270M (Duo/WeddingBook 2025). This guide breaks down allocation across venue, home, gifts, and honeymoon.
- Wedding budget
- Korean wedding
- Cost
Guide · 2026-04-27
24Annual-Salary Letter vs. Labor Contract — Differences & Drafting Guide (2026)
An annual-salary letter does NOT replace a labor contract. This guide explains the legal difference, 11 mandatory items for 2026, and frequently-omitted clauses.
- Labor contract
- Salary letter
- HR
Guide · 2026-04-27
25Korean Inclusive-Wage Contract — 5-Minute Legality Self-Check (2026)
A self-check against Supreme Court precedent (2010Da91046) for the 5 legality requirements of Korean inclusive-wage contracts, plus a workflow to recover unpaid overtime/night/holiday wages.
- Inclusive wage
- Overtime pay
- Labor Standards Act
Blog · 2026-04-27
26Jeonse vs. Monthly Rent in Korea — Case-by-Case Analysis (2026)
With jeonse-loan rates near 5% and conversion ratios at 5.5%, this guide compares jeonse vs. monthly rent across 4 deposit/duration cases.
- Jeonse
- Monthly rent
- Housing cost
Guide · 2026-04-27
27Korean Capital-Gains Tax Exemption — 5 Conditions (2026 Edition)
The five Korean capital-gains tax exemption conditions for 2026 — one-home household, 2-year holding, 2-year residency, temporary 2-home, and inheritance/rural exceptions.
- Capital gains tax
- One-home exemption
- Korea property tax
Guide · 2026-04-25
28Korean Jeonse Fraud Prevention in 7 Steps (2026 Edition)
A 30-minute self-diagnostic — registry check, market price, debt ratio, and HUG insurance eligibility — to avoid Korean jeonse fraud.
- Jeonse fraud
- Underwater deposit
- HUG
Guide · 2026-04-20
29Coupang Seller Onboarding — From First SKU to Break-Even
A practical playbook for new Coupang sellers — set first-SKU pricing and break-even using category fees, RocketGrowth, and ad ROAS.
- Coupang
- Seller
- RocketGrowth
Blog · 2026-04-15
30Korean Driver-License Renewal 2026 — Aptitude Test, Fees, and Online Filing
A one-page reference: renewal cycle by license class, aptitude-test thresholds, and how to file via the KOROAD safe-driving portal.
- Driver license
- Aptitude test
- KOROAD