Waitiii

Context

Physical queues generate customer abandonment, frustration and wasted time for merchants. Existing solutions are either too expensive or too rigid for local businesses. Waitiii digitizes the queue: customers scan a QR code, track their position in real time on their phone and receive a notification when it's their turn. Merchants manage their queue from a dedicated app with statistics and team management tools. This is the only project in the portfolio with recurring revenue and real daily users — paying clients since September 2025.

Architecture

The ecosystem covers the entire user journey through four functional blocks.

The real-time API is the system's core. It manages queue state in real time via WebSocket, instantly synchronizing every position change between the merchant and all connected customers. The backend also handles subscription and payment management, multi-channel notifications (SMS, push, email) and role-based authentication (admin, team, customer).

The two React Native mobile apps cover both sides of the product. The customer app provides a smooth flow: QR scan, registration, real-time position tracking with animated counter and push notifications. The professional app is a full management tool: queue control, next customer call, team management, detailed statistics and QR code generation.

The web interfaces combine a React app for the real-time queue experience and a Next.js site (TypeScript, Tailwind) for SEO content. The latter integrates a programmatic SEO strategy with AI-powered automated blog article generation, scheduled indexing and planned publication to maximize organic search visibility.

The admin dashboard provides full operational control: CRM, analytics, subscription management and billing.

Technical challenges

Multi-instance real-time under load. Dozens of businesses with simultaneously connected customers means hundreds of WebSocket connections to maintain. The system synchronizes queue state across multiple server instances through a Redis message bus. Each update is broadcast only to the relevant business's connected clients. On mobile, an automatic reconnection mechanism handles background/foreground transitions and network drops.

Dynamic wait time estimation. A naive estimate (position x average time) is systematically wrong: service times vary by service type, time of day and number of active agents. The algorithm combines the business's history, time slots and current load to produce a realistic estimate. A scoring system compares estimates to actual times to continuously improve accuracy.

Multi-channel notification orchestration. When a customer is called, the notification must arrive immediately, on the right channel. The system orchestrates four channels — SMS, WhatsApp, push and email — each with its own throughput constraints and formats. A fallback mechanism automatically switches to the next channel if the first one fails.

Project scale

• Backend: Node.js/Express API, PostgreSQL, real-time WebSocket, automated cron jobs
• Mobile: 2 React Native apps (customer + professional), Redux, push notifications, QR codes
• Web: React app (real-time) + Next.js site (SEO, AI blog, TypeScript), i18n FR/EN
• Business: Stripe payments, 4 notification channels, 6 repositories, paying clients in production

Current status

In production since September 2025 with paying clients using the platform daily. The marketing site has been migrated to Next.js with TypeScript and Tailwind. The programmatic SEO strategy is operational with scheduled publishing.