Sangyoon Lee
Kraj: South Korea
Lokalizacja: Seoul, KR
Na Useme od 21 września 2026
O mnie
Inżynier full-stack, 12+ lat (web, mobile, backend). Prowadzę produkt od pierwszego commita do produkcji i dbam, żeby działał.
- Wymieniłem cały backend działającej aplikacji (serverless na Spring Boot) bez wymuszania aktualizacji aplikacji. - Zbudowałem 3 nowe serwisy w 2 miesiące, sam, terminy dotrzymane. - Przez 2 lata prowadziłem aplikację Flutter od A do Z: backend, płatności subskrypcyjne, logowanie, wydania. - 10 lat systemów czasu rzeczywistego; 4 rodzaje integracji płatności na produkcji. - Ostatnio: serwer MCP open source dla Google Search Console, wtyczka WooCommerce, rozszerzenia IDE.
Stack: Node/TypeScript, Python, PHP/Laravel, Java/Spring Boot, React, Flutter, PostgreSQL, Redis, Docker, AWS.Pisemnie: każde żądanie i zmiana zakresu są zapisane; odpowiadam w 24 h, też w weekendy. Przed kodem: specyfikacja z listą odbioru. Seul, prawdziwe imię, tożsamość zweryfikowana; moje prace są publiczne w JetBrains, VS Code, WordPress.org i Atlassian. Płatność tylko przez etapy Useme.
Kategorie
CV / Résumé
Lip 2024 - Lip 2026
Lead Engineer
Wego Company
Built a kids news app (Flutter, iOS and Android) for a newspaper subsidiary. Rebuilt the backend on Spring Boot WebFlux with a GraphQL API, integrated one-off and recurring subscription payments, Google and Apple sign-in, and realtime features over G
Portfolio
Daily cron pulls a government open API, cleans the records and generates about 350 statistics pages on Cloudflare Workers and D1. Built solo, from the scraper and the schema to the pages and the deployment.
Spreadsheet reporting automation
Order and sales sheets that update themselves: raw rows in, cleaned data and a summary dashboard out, with formulas and scripts instead of manual copying. Delivered to paying customers on a Korean freelance marketplace.
My own SaaS, live. Connects Google Search Console to Claude and ChatGPT over MCP, mails a weekly report with 3 things to fix, and alerts on click drops. Built and operated solo: Cloudflare Workers, D1, OAuth, billing.
Extension published on the Visual Studio Marketplace. Re-runs .http request files and compares the responses, a lightweight API regression test inside the editor. Passed marketplace review.
Plugin listed on WordPress.org. Keeps Printful print-on-demand products in step with WooCommerce without deleting anything silently and without touching the customer cart. PHP, WooCommerce hooks, Printful API.
Jira dashboard gadgets (Atlassian Marketplace)
Gadgets published on the Atlassian Marketplace: goal gauge, countdown and filtered issue list. Atlassian Forge, React, Forge storage. Passed Atlassian security review and is live for public install.
Excel merge and cleanup macro
Merges many Excel files into one table, normalises columns and dates, removes duplicates and produces the summary sheet. Work that took a morning by hand now runs in one click. Sold as a product with real buyers.
Live service that finds and blocks invalid clicks on Korean search ads automatically. Detects repeated clicks from the same visitor, builds the block list and applies it. Built and run by me end to end: backend, scheduler, dashboard, Cloudflare deplo
Paid plugin on the JetBrains Marketplace (one of 7 I published). Renders Markdown in a real browser engine, follows the IDE theme, supports Mermaid diagrams. Java, IntelliJ Platform SDK. Passed JetBrains review.
Returns Google Trends interest over time, by region and related queries. Handles the 429 rate limit with cookie warm-up and proxy rotation so runs finish instead of hanging until the platform timeout.