我關注那些藏在系統背後、但會決定它能不能長期維護的東西：
身份權限、內部流程、服務邊界、維運工具與交接文件。
English Version
I focus on the parts behind software systems that determine whether they can be maintained over time: identity, internal workflows, service boundaries, operational tools, and handover documentation.
身份、驗證與授權不只是登入功能，而是產品、團隊與責任邊界的一部分。 我整理 IAM、SSO、Keycloak、JWT 與 role model 相關的設計，讓權限邊界在系統成長後仍然能被理解與維護。
Identity and access management is not only about login. It defines product boundaries, team responsibilities, and operational risk. I work on IAM, SSO, Keycloak, JWT, and role models that stay understandable as systems and teams grow.
常用技術：Java · .NET Core · PostgreSQL · IAM · SSO · Keycloak · JWT
很多重要的系統問題不在產品畫面上，而是在內部流程、資料狀態、權限邊界與日常作業裡。 我喜歡把這些分散的流程整理成可追蹤、可維護、能交接的內部工具與平台。
Many important system problems do not appear on the product surface. They live in internal workflows, data states, access boundaries, and daily operations. I build internal platforms and tools that make those workflows traceable, maintainable, and easier to hand over.
常用技術：React · .NET Core · PostgreSQL · Redis · Docker
重複流程如果沒有被整理，最後會變成團隊每天都要承擔的隱性成本。 我把容易漏接、難追蹤、需要跨系統協作的流程，整理成可靠、可觀測、能持續調整的系統。
Repetitive workflows become hidden operational cost when they are not organized. I turn fragile, cross-system processes into reliable, observable, and adjustable workflows.
常用技術：Docker · GitHub Actions · API Design · System Integration
好的交接文件比聰明的架構更重要。 我會把系統設計、重構決策、維運經驗與團隊流程寫下來，讓後面接手的人不用重新踩一次相同的坑。
Good handover documentation is often more valuable than clever architecture. I write system notes about design decisions, refactoring, operations, and team workflows so that future maintainers do not need to rediscover the same context.
常見主題：System Design · Refactoring · Maintenance · Documentation · Operational Clarity
Not every system problem becomes a product feature. Some become tools, experiments, diagrams, notes, or rules of thumb.
不是每個系統問題最後都會變成產品功能。有些會變成工具、實驗、圖、筆記，或某種反覆被驗證的判斷方式。
日常開發中反覆出現的小問題：格式轉換、token 檢查、資料整理、時間換算、JSON、SQL、JWT。 這些東西不大，但會打斷工作。我把它們整理成可以重複使用的小工具。
Small utilities for repetitive development tasks: formatting, token inspection, data cleanup, timestamp conversion, JSON, SQL, and JWT. They are not large systems, but they reduce small interruptions that accumulate over time.
一些 local-first 的系統實驗，用來拆解平常藏在企業系統背後的問題：gateway、API、database、cache、metrics、dashboard、CI、IAM 與服務邊界。
Local-first system experiments for making hidden infrastructure concerns visible: gateway, API, database, cache, metrics, dashboards, CI, IAM, and service boundaries.
- local-platform-engineering-lab — local environment covering gateway, API, database, cache, metrics, dashboards, and CI wiring
- local-platform-iam-lab — local IAM experiment with Keycloak, SSO, JWT, and role model exploration; companion to the IAM work above
一些可以被重複拿來討論、修改或延伸的後端架構底稿。
它們不是追求最新寫法的樣板，而是用來整理企業內部系統常見的限制：舊資料庫、身份驗證、交接維護、本機開發、設定管理與部署邊界。
Reusable backend architecture bases for discussing, adapting, and extending enterprise internal systems.
They are not meant to be perfect greenfield templates. They are shaped around common enterprise constraints: existing databases, authentication, handover, local development, configuration, and deployment boundaries.
- NETCoreBase — legacy-friendly ASP.NET Core enterprise API base for JWT auth, DB First workflows, Docker-based local development, and handover-ready maintenance.
- JavaSpringBase — Spring Boot enterprise API base for JWT auth, IAM integration, layered architecture, and handover-ready Java backend maintenance.
工程工作裡留下來的筆記。 系統維護、重構決策、交接文件、團隊流程。不是教學文，更多是實際遇到問題之後的整理。
Notes from engineering work: system maintenance, refactoring decisions, handover documentation, and team workflows. They are less like tutorials and more like records of what became clear after dealing with real problems.
→ my-blog
- 🌐 Website — 工具、實驗、文章與更完整的整理
- ✍️ Blog — 系統設計、IAM、平台工程與維護筆記
- 🧰 GitHub — 工具、實驗與公開專案
- 💼 LinkedIn — 工作經歷與專業連結
- Email: chenpoyu1123@gmail.com
- Website: poyu-chen.pyvot.uk
- Blog: poyu-chen.pyvot.uk/my-blog
- LinkedIn: poyu-chen-207204191