Bill Lin

Hi, I'm

Bill Lin

Senior Backend Engineer

Working in Taipei, Taiwan

Senior backend engineer with 7+ years on Java / Spring, mostly on billing & payment systems. Cross-trained on Vue / React and Kotlin for Android — the frontend background helps me ship full-stack, but I focus on the server side.

This site is where I keep my engineering notes.

GitHub LinkedIn Email

Last updated 2026-04-28 · For full CV see LinkedIn

Experience

7+ years · Java backend

  1. Software Engineer

    2021/07 — Present

    104 Corporation · New Taipei City, Taiwan

    • Built and maintained the billing & payment platform serving 7 business units.
    • Led on-prem → AWS migration; cut weekly maintenance incidents 2–3×.
    • Built E2E tests with WebdriverIO; eliminated 30+ min manual QA per release.
    • Internal speaker (200+ engineers): Kotlin migration, GraalVM, API-first design.
    Spring Boot MySQL AWS Kotlin TypeScript

  2. Software Engineer

    2020/08 — 2021/03 · 8 mo

    CASHIER TECH. CORP., LTD. · Xizhi, New Taipei

    • Spring Boot backend for a kiosk ordering system across 50 stores.
    Spring Boot Android Kotlin

  3. Software Engineer

    2019/09 — 2020/07 · 11 mo

    Hongyang Tech · on-site at Far EasTone

    • Lease management forms and CRUD APIs at a telecom client site.
    Java Oracle

  4. Software Engineer

    2018/01 — 2019/01 · 1 yr 1 mo

    Eagle Industry Taiwan · Kaohsiung

    • Internal e-portal for a 500-person company.
    Java JSP Servlet

Skills

Languages

Java Kotlin TypeScript

Exploring: Python · Go

Backend

Spring Boot JPA / Hibernate MySQL Redis

Frontend (light)

Vue.js React

Cloud / Tools

AWS Docker GraalVM Git

Certifications

Industry Certifications

Oracle Certified Professional, Java SE 6 Programmer

Oracle · 2016/06

Planner of Enterprise Resource Planning

ERP Certification

Online Courses

Certificate of Completion: Claude 101

Anthropic · 2026/03

Claude Code in Action

Anthropic · 2026/01

Recent Writing

All posts →

網頁憑證信任圖解：TLS 握手、憑證鏈、Trust Store 到 openssl 排錯

圖解網頁憑證信任：TLS 1.3 握手、X.509、憑證鏈與 Root CA、trust store、wildcard/SAN、防火牆 SSL inspection、HSTS、過期續約，附 openssl 與 Java 實測排錯

· Security

grep — 文字搜尋、正規表達式與 Log 排查命令列指南

grep 完整指令筆記：-i -v -w -o -c 等常用旗標、前後文與遞迴搜尋、BRE/ERE/PCRE 正規表達式、macOS BSD 與 GNU grep 差異，以及 Log 排查實戰

· CLI

openssl — 憑證、加密與 TLS 除錯命令列指南

openssl 完整指令筆記：macOS LibreSSL 與 Homebrew OpenSSL 差異、憑證與金鑰操作、TLS 連線除錯、加密雜湊亂數與格式轉換實戰

· CLI