mDealer
Overview
SaaS for car service shops: booking by service bay, work orders with parts and payments, inventory, a deal pipeline and an API for existing integrations.
- Year
- 2026
- Type
- SaaS · Own product
- Role
- Design and full-stack development
- 478
- automated tests
- 56
- data models
- 25
- API modules
Challenge and solution
The challenge
Repair shops juggle bookings, work orders, stock, payments and customer messages across several tools — and their customers get no app at all.
The solution
A multi-tenant SaaS: a Fastify and Prisma API with strict per-shop isolation, a staff app for the whole workflow including 1C export, and a separate app for car owners. A Claude-based assistant sends maintenance reminders and books customers into free slots.
Screens
What it does
- Sign-up for shops with 4 roles and email invites
- Booking calendar by service bay with double-booking protection
- Work orders, estimates, diagnostics and invoices with parts and labour
- Deals on a kanban board with custom stages, plus tasks
- Inventory: receipts, transfers, write-offs and stock counts
- “My car” app for owners: history, live repair status, online booking
- AI assistant that chats with customers over WhatsApp and Telegram
Under the hood
- Tenant isolation inside Prisma: every query gets the shop’s ID automatically; audit log written by database triggers.
- Postgres advisory locks stop two bookings from taking the same bay and slot.
- Claude tool-use loop with a Redis queue that merges a burst of messages into one reply.
- Export to 1C:Accounting in EnterpriseData XML; chunked uploads with ffmpeg transcoding.
- Next.js
- React
- Tailwind CSS
- Fastify
- PostgreSQL
- Prisma
- Redis
- Zod
- Claude
- Docker
- Coolify