I'm Junhua, an independent developer. Alongside my own products, I take on a small number of freelance projects. Everything below is live, and I designed, built, and still run each one, so the links are the best way to judge the work.
Single-purpose pages with the tool at the top, fast on a phone. Data can stay in the browser, with share links, print, and export.
Stripe Checkout and the unlock step after payment, tested end to end in sandbox before any real money moves.
Moving sites to Cloudflare one step at a time, keeping email records intact, with a written rollback for each step.
Google Search Console, Bing Webmaster Tools, IndexNow, sitemaps, canonical URLs, and structured data for new or migrated sites.
Native macOS apps with local-first data and menu bar features, and Flutter apps for iPhone and Android, from first build to store release.
Connecting AI to a real product: an MCP server that Claude and Codex can use, or model-generated content inside an app.
A local-first Mac app for revenue, scheduled costs, and estimated contribution profit across software products.
Chinese astrology (BaZi) calculators where the hard part is time: historical time zones, true solar time, and solar-term boundaries.
Wedding planning tools (timeline, checklist, budget calculator, guest list, and seating chart maker) that work without an account.
Turns a webpage, PDF, or pasted text into a quiz, and keeps a notebook of the questions you get wrong.
Moved my company's website from Firebase Hosting and Amazon Route 53 to Cloudflare without breaking its email, then redesigned it.
A 60-second mental-math game with four modes and global leaderboards.
Email me what you want to build, your timeline, and a rough budget. If it looks like a good fit, I'll reply with questions or a short plan.