SG
04Engineering Work

PlaceMate

I kept forgetting where I had stored important belongings.
01A privacy-first physical inventory system that never leaves the device.

Problem

People frequently forget where they have stored important physical possessions. Traditional inventory applications often require cloud storage and compromise user privacy.

Context

Goal: build a privacy-first physical inventory management system that stores sensitive information entirely on the user's device. Philosophy: sensitive physical inventory should never leave the user's control.

Engineering Decisions

Prioritised privacy, offline capability, local ownership, and security over convenience features like sync or collaboration.

Trade-offs

Accepted no cloud sync, no collaboration, and no remote access in exchange for keeping data entirely local.

Architecture

Client-side, browser-only architecture. No server component; all data is stored and encrypted on-device.

Implementation

Natural language storage and conversation-based retrieval. AES-256 encryption with PBKDF2 key derivation for encrypted local storage. Recovery phrase system and password rotation.

Lessons Learned

Security is only valuable when it remains usable.