This system connects overtime submission, manager review, role-based access and administrative consolidation in one workflow. It is currently used internally by the Center for Teaching and Learning Development, Office of Academic Affairs, National Cheng Kung University (NCKU).
Real-world use: NCKU Center for Teaching and Learning Development. Official unit website ↗. Production accounts, databases and staff data remain private. This portfolio entry does not imply institutional endorsement of the public repository; formal overtime recognition remains subject to university systems and procedures.
In use at NCKU Center for Teaching and Learning Development
Stack
React · Vite · Cloudflare Workers · D1
Year
2026
00 / Project framing
Project framing and engineering decisions
ProblemWhen overtime data is scattered across messages, forms and manual consolidation, manager review, tracking and administrative reporting become harder to maintain.DecisionUse a React frontend with a Cloudflare Worker API and D1 to keep submission, approval, role controls and reporting in one workflow, with server-side time and overlap validation.EvidenceThe system is currently used by NCKU’s Center for Teaching and Learning Development; the public portfolio snapshot exposes only reviewable code and synthetic data, not staff data, credentials, databases or the production entry point.NextFuture work could strengthen audit trails, export formats and integration with formal university workflows; the portfolio does not claim those as completed features.
01 / Workflow
More than a form: one administrative workflow.
Employeedate, time, reason and requested hours
Managerpending queue, approve or reject
Secretary / Adminconsolidation, users and role controls
D1requests, users, sessions and approval logs
02 / Backend rules
Time validationThe backend revalidates start time, 30-minute intervals and requested duration instead of trusting frontend input.Overlap controlExisting non-rejected requests are checked for overlapping time ranges before a new request is accepted.Role boundaryEmployees, managers, secretaries and administrators have different read/write permissions, with sensitive API actions authorized server-side.Session securityFirst-login password changes, PBKDF2-SHA256 password hashing, hashed session tokens and HttpOnly cookies.
03 / Production boundary
Real use is separated from the public portfolio.
The production environment is operated for the actual internal workflow and is not exposed as a portfolio login target.
The public source excludes real names, email addresses, overtime reasons, passwords, tokens and production D1 identifiers.
The portfolio describes the workflow and implementation without presenting it as an “official NCKU overtime system.”
Formal overtime submission, recognition and reimbursement remain subject to university systems and procedures.
04 / System view
The public portfolio exposes the system architecture and reviewable code, not production staff data or the operational entry point.
05 / Takeaway
The value is turning a routine administrative problem into a tool people actually use.
The project is not only about React or Cloudflare. It organizes submission, review, authorization and consolidation into a usable workflow that has entered real internal use at NCKU CTLD.
