Peter Wang
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Preventive maintenance platform

Known internally as PM Log.

Sole frontend developer. Schema and API design lead.

Scheduling and execution tracking for machine maintenance, used across 30%+ of manufacturing.

30%+
of manufacturing using it
10k+
records cached client-side
4
level hierarchy

machine, checklist, section, task

A React platform for planning and recording preventive maintenance, replacing paper and spreadsheet tracking. It has two distinct faces. Administrators author and maintain the maintenance definitions; operators work through what is actually due.

The data model is a four-level hierarchy (machine, checklist, section, task), and the administrative side allows editing at any level of it. You can open a checklist, edit down through its sections to individual tasks, and revert the entire tree of changes in one action. Making that feel immediate meant caching 10k+ ID-linked records in Jotai and treating the client cache as the working copy, with the server reconciled on commit rather than on every keystroke.

The operator view answers a different question: what needs doing first, what is coming up, and which line and machine it belongs to. Same data, ordered by urgency instead of by structure.

React, TypeScript, Jotai, Tailwind CSS