Selected work

Project

03 of 06

Discipline

Software

SWL Pricing and Inventory Control

A local-first pricing and inventory control application with a Windows desktop surface and a browser surface. It compares an untouched supplier export against the current ServiceM8 materials list, applies the confirmed 30 percent markup on GST-exclusive cost, and produces an operator-reviewed import CSV in ServiceM8's exact format, with change, exception, rollback and audit reports.

Screenshot of the SWL Pricing and Inventory Control new-run screen showing the seven-stage workflow from adding files to a reviewed export, with the current business rules panel.
Application interfaceFull-size image ↗

Problem

Stan Wootton Locksmiths reprices its ServiceM8 materials catalogue from supplier price exports. Doing that by spreadsheet risks damaged item numbers and barcodes, an inconsistent markup and unreviewed price changes reaching the job system.

Architecture

A shared React and TypeScript interface over pure domain modules for money, pricing, comparison, mapping and output. A typed platform adapter selects the backend: scoped Tauri commands with bundled SQLite on the Rust desktop build, a loopback Node server for local web use, and a session-only store for the static demonstration.

Design decisions

  1. Matching is deterministic and fail-closed: exact normalised code, then operator-approved alias, then description similarity as a suggestion only. Items missing from a supplier file are never deleted, and money is never binary floating point.
  2. Imported business rows stay in memory and are never persisted; repository checks and CI enforce a no-production-data and no-secrets rule on every change.

Verification

More than 500 automated checks: Vitest unit and property-based tests, Playwright browser tests with axe accessibility runs, WebdriverIO tests against the installed desktop app and Rust unit tests, including a byte-for-byte round trip of the ServiceM8 CSV contract. Typecheck, lint, tests and packaging run in CI.

Engineering case study

Read the design rationale, verification scope and proposed next experiments.

Read the SWL Pricing and Inventory Control case study

Continue the conversation.

Have a related engineering problem? Get in touch or explore another project.

Email Saj Resume PDF Next: Gendio Display Controller