Axto

What it does

Axto connects auto parts buyers and sellers. Buyers browse listings through a React Native app; sellers manage inventory, process orders, and track analytics through an Astro web dashboard. Vehicle compatibility matching ensures you only see parts that fit your car.

Architecture

Two frontends, one backend:

• Mobile app — React Native (Expo). Browse by vehicle, search by part, save favourites, direct messaging with sellers. Push notifications for price drops and saved searches.
• Admin dashboard — Astro with React islands. Inventory management, order fulfilment, sales analytics. Responsive — works on desktop and tablet.
• Backend — Supabase handles auth, Postgres with Row Level Security, storage for part images, and real-time subscriptions for messaging.

Key decisions

Vehicle compatibility as a graph problem. Instead of tagging every part with make/model/year (which is thousands of combinations), we modelled it as a compatibility matrix — each part has a set of "fits" rules, and the query engine walks the graph. More work upfront, but adding a new vehicle doesn't require retagging every part.

Supabase RLS for multi-tenant data. Every row in the database has a seller_id, and Row Level Security policies enforce that sellers only see their own orders and inventory. Buyers see only public listing data. This means the mobile app queries Postgres directly — no custom API layer needed for reads.

Scope management is a skill, not a constraint.

The hard parts

Search. Postgres full-text search is fine for text, but auto parts have VIN-specific queries, OEM numbers, and fuzzy brand matching. We ended up with a hybrid: Postgres tsvector for full-text + a custom matching layer for compatibility queries.

Image moderation. Users upload part photos. We built an automated moderation pipeline using a third-party API, but the false-positive rate on engine parts vs. prohibited items was… educational.

Screenshots

What I learned

This was my first full-stack marketplace and the project where I learned that scope management is a skill, not a constraint. The feature list kept growing — reviews, messaging, notifications, analytics — and each one taught me something about state management across platforms, real-time data sync, and why you don't skip writing integration tests for your Stripe webhook handler.

Also: React Native's FlatList performance with 10,000+ parts listings is genuinely impressive. Astro's partial hydration meant the dashboard felt instant despite having React components embedded in static pages.