About this site
Hi, I'm Mark Liu, a QA engineer in fintech who turned my most-used daily utilities into this public site.
My background
I work at a Taiwan-based fintech company building test frameworks, designing automation for APIs and mobile apps, and running QA processes. My day-to-day toolkit: - Robot Framework (API + Web E2E) - Playwright (Web automation) - Appium (iOS / Android automation) - JMeter / k6 (load testing + percentile analysis) - Postman / cURL / HTTPie (API testing) - Docker / Jenkins / GitHub Actions (CI/CD) Most tools on this site are things I personally reach for every day — that's why pain points are real (see percentile calculator, JWT decoder, selector tester, Taiwan test data).
Why I built this
After enough years of QA work I noticed: 1. Most micro-tools want you to upload files to their server — useless for anything sensitive from work. 2. Sites are drowning in ads — you scroll for ages just to find the input box. 3. Chinese-language coverage is poor — Taiwan / Hong Kong QA folks often have only Simplified Chinese to read. So I set three rules for this site: - No uploads: files never leave your browser. Everything runs locally in JavaScript / WebAssembly. - No paywall, no limits: no Pro tier, no watermarks, no "free 3 times then pay". - No ads: no Google Ads, no AdSense, no affiliate marketing (only non-advertising GA4 for traffic analytics). The privacy page lists every data flow, and every line is open-source and auditable.
Open source + transparent
The whole site is 100% open source — verify there's no upload logic yourself: - Repo: github.com/MarkwwLiu/dev - Stack: Next.js 16 + Tailwind v4 + next-intl + Vercel - License: Proprietary (source is public, rights reserved) Found a bug, want a new tool, or have an idea? Open an issue or PR on GitHub.
Contact
- GitHub Issues: MarkwwLiu/dev/issues (preferred — public + trackable) - Email: ak790718@gmail.com - Other projects: Stackr (ticketing system for solo + small teams), cv.9niche.com (résumé)