trafe: Software for car rental companies.

The challenge

Many car rental companies still work with paper contracts, spreadsheets and photos on private phones. Handovers take time, damage is hard to prove in a dispute, and forged IDs are a real risk — a single misappropriated car quickly costs more than any software. trafe is our answer: our own product, which we have been developing, operating and marketing as a sister brand since 2021.

What trafe does

• Booking & calendar: reservations, availability and fleet at a glance — at the desk and on the go.
• Automatic rental contract: contracts, confirmations and invoices are generated from the booking data. Nothing is ever typed twice.
• Digital handover & return: reports with photo documentation right in the app, offline-capable, signed on the device.
• Fraud protection: IDs and driving licences are checked for authenticity with a document reader.
• Risk management: integration of common GPS trackers, alerts on anomalies.
• Maintenance & deadlines: inspection plans, damage history per vehicle, reminders for MOT/emissions tests.
• White label: app and software appear in each rental company's design and logo.
• Fines & authority requests: record tickets, assign them to the right renter, output them as PDF and recharge them; handle authority requests such as driver identification in a structured way.
• Car subscription: inquiries, contracts from templates, invoices, dunning, damage reports and documents — for rental companies that offer subscriptions alongside short-term rental.
• Own booking website: vehicle catalogue, online booking, location map and a customer account with contracts, messages, damage reports and handover confirmation — in the rental company's design.

Technology

trafe consists of four building blocks working together via one shared API — each multi-tenant, so every rental company only sees its own data.

• App: Flutter 3 with Dart, around 680 source files in clean architecture with BLoC — one codebase for iOS, Android, web, Windows, macOS and Linux. Text recognition via ML Kit, document edge detection, barcode and QR scanner, digital signature, PDF generation and printing, multilingual.
• Backend: Node.js with Express, MySQL with Sequelize and Drizzle migrations, JWT authentication, rate limiting, encrypted API responses, PDF contracts and mail templates — built as a Docker image.
• Booking website: Next.js 16 with React 19, strict TypeScript and Tailwind, multilingual with next-intl, map views with Mapbox, newsletter integration, tests with Vitest.
• Admin centre: Next.js 16 with Material UI — dispatch board, prices and tiered prices, extras, vouchers, car-subscription management, mail templates and design, legal texts and website content; end-to-end tests with Playwright.
• Integrations: document reader for IDs, GPS trackers, invoicing.

Delivery per rental company

Every rental company gets its own app in the stores and its own website — fully automated from one codebase.

• Releases by tag: one version tag builds web, Android and iOS for all active customers in parallel — or for a single customer.
• Own store listings: fastlane creates a separate app on Google Play and the App Store per rental company, including TestFlight distribution.
• Containers & GitOps: the web version is built as an immutable container image; an automated pull request sets the new version in the Kubernetes cluster and Argo CD rolls it out. Every previous version can be restored exactly.
• Quality & operations: type checks, linting, tests and dependency checks in the pipeline, plus runbooks for releases, store onboarding and key rotation.

Infrastructure

trafe does not run in an anonymous public cloud but on its own infrastructure operated in Germany — GDPR-compliant and fully under control.

• Kubernetes cluster: managed with Rancher, 9 nodes in three groups — Rancher nodes, control plane and workers, each tripled.
• GitOps with Argo CD: every change is versioned, reviewed and rolled out reproducibly.
• Virtualisation: Proxmox on dedicated bare-metal servers in German data centres — no shared hardware.
• Backups: Proxmox Backup Server with regular, versioned backups.

Brand & market

Circle Studio owns the presence: brand and positioning, the product website trafe.io with comparison and knowledge pages for search engines and AI assistants, and trade-fair appearances — for example with its own stand at the “Flotte!” fair in Düsseldorf. According to trafe, more than 200 rental companies now use the software.