Replacing the paper HACCP binder with a tool that keeps up with service.

Context

In France, every restaurant is legally required to keep an HACCP log: daily temperature readings, product traceability, expiry date management, cleaning schedule. Traditionally, all of this happens on paper — time-consuming, error-prone and dreaded on DDPP food-safety inspections.

Quality Food digitises the whole process: the operator scans products, prints expiry-date labels on a thermal printer, fridges are monitored by IoT sensors, and audit reports are generated in a click.

My role

Sole developer of the product, from v1.0 to today — design, development, hardware integrations, monetisation and continuous maintenance, on behalf of Coding Industry. The client is based in Paris, full remote from Yaoundé.

What was delivered

Full HACCP compliance

• upstream and downstream food traceability with mandatory photos as evidence;
• manual or automated temperature readings from cold and hot equipment;
• cleaning plan: scheduling, validation with photo proof, per-user follow-up;
• digital receiving inspection and multi-supplier management;
• document management with 8-category organisation;
• CSV exports and audit reports ready for DDPP inspections.

Hardware and service integrations

• expiry-date label printing on a Brother QL-1100NWBc thermal printer;
• Koovea IoT temperature sensors: continuous monitoring, ±0.2 °C precision, real-time alerts;
• barcode scanner with automatic product-sheet retrieval via the Open Food Facts API.

Experience and monetisation

• task-creation assistant (daily, weekly, monthly);
• push notifications: expiry-date warnings, cleaning deadlines, temperature alerts;
• trilingual app: French, English, Arabic (full RTL);
• 14-day free trial then subscription — onboarding under 15 minutes.

Structural decisions

UX for restaurateurs, not for developers

The biggest challenge was neither the hardware nor the backend: it was designing interfaces a restaurateur understands immediately, while letting them capture and analyse information quickly. In the kitchen every second counts: a temperature reading has to take three taps, a label has to print without thinking, the manager has to see compliance at a glance.

A software + hardware ecosystem

Making a Flutter app talk to a Brother thermal printer (label formats, print queue) and Koovea sensors (continuous telemetry, alert thresholds, audit history) — reliably enough to serve as legal evidence during a food-safety inspection.

Full serverless Firebase

Six services orchestrated — Firestore, Auth, Cloud Functions, Storage, FCM, Remote Config — for controlled operating costs and automatic scalability. Product configuration can evolve without a new release via Remote Config.

Dual payment loop

RevenueCat for iOS and Android in-app purchases (store compliance) and Stripe for SEPA and card subscriptions on the web — with 14-day trial handling and subscription tiers.

Advanced internationalisation

Trilingual including Arabic, so full RTL: mirrored layouts, icon alignment, reading direction for dates and numbers, bidirectional forms. A skill rarely seen in Flutter developers.

A living product for two years

Shipping a v1 in two months is one thing; keeping a product alive for nearly two years is another. The public release history shows a sustained rhythm: CSV export, richer notifications, EN then AR translations, automatic temperature reading, document management, barcode scanner, filtered exports — each release answering restaurateur feedback.

What this project proves

• Flutter production-ready over the long haul (iOS and Android, phone and tablet);
• full mastery of the serverless Firebase ecosystem;
• hardware integrations: networked thermal printing, IoT sensors;
• professional SaaS monetisation: RevenueCat, Stripe, free trials;
• trilingual internationalisation with RTL support;
• sole developer end-to-end: spec, design, dev, integrations, publishing, two years of maintenance;
• UX design for non-technical users in constrained environments.

Honesty note

Some commercial figures reported by the client (25 restaurants subscribed, ~60 % trial-to-paid conversion, -40 % measured waste, near-zero churn) come from an internal environment. They can be presented in interviews with the appropriate sources but are not shown here as public evidence.