THON Hermès

Direct clients in fintech, social and mobility.

• RYZ — social network with real-time messaging and audio/video calling via Stream SDK, holding 10,000+ concurrent connections. Layered architecture with Riverpod.
• Tap&Eat and Locars — FedaPay gateway integration for mobile money and cards, 500+ transactions per day. Confirmation webhooks, PCI-DSS compliance.
• Dossi — SMS OTP authentication via FasterMessage, 99.7% delivery rate, real-time transaction notifications.
• Serverpod and Rust (Actix-web) backends — under 50 ms latency on critical endpoints.
• Full App Store and Play Store releases: Apple Sign-in, App Privacy labels, Data Safety.

Flutter · Dart · Riverpod · SwiftUI · Serverpod · Actix-web · Firebase · FedaPay

• Flexycash, a payment app — API error handling and automatic retry, 35% fewer failed transactions.
• Justwell and Aquiletour, consumer apps with 50,000+ active users — 40% UI performance gain, complex state management.
• Third-party API integrations and 20+ critical production bugs fixed, 99.5% uptime.

Flutter · Dart · Firebase · REST · Git · CI/CD

• Social network with instant messaging and real-time push notifications (FCM), optimistic sync with no perceptible latency.
• Logistics app — real-time order tracking, Google Maps API, geolocation accurate to 10 m, secure payments.
• Owned the architecture decisions (MVVM, Clean Architecture) — 30% less maintenance time.

Flutter · Firebase · Google Maps API · MVVM · Clean Architecture

• Ported an invoicing product to mobile with real-time local ↔ remote sync, 200+ invoices per day.
• Real-time stock and sales management across 15 service stations.
• FasterMessage integration for OTP validation — 99.5% reliability.

Flutter · SQLite · FasterMessage API · Real-time sync

• Full-stack development of web platforms on Symfony (PHP).
• Native Android applications in Java — 25% performance gain.

Symfony · PHP · Java · Android SDK

• Makes an app local-first on top of an existing backend, without rewriting its models or imposing a database.
• Per-field merge on a logical clock, queue drained on confirmation only, schema replicated with no on-device migration.
• 500 generated conflict scenarios under test, end-to-end tests over a real socket. Optional reference hub in Rust.

Dart · Drift · Rust (axum) · WebSocket

• Brings Liquid Glass widgets to Flutter, with graceful degradation: on iOS versions without Liquid Glass, each widget renders its standard native counterpart rather than an imitation.
• API design, version gating and documentation for a package meant to be consumed by other teams.

Flutter · Dart · Swift · platform channels

• Subset search with partial matching and weighted ranking — also surfaces recipes that are one or two ingredients short.
• Inverted index from ingredient to recipes, running locally and offline, instant results.

Flutter Web · Drift

• Real scheduling rather than another task list: multi-calendar free/busy (CalDAV, EventKit, Google Calendar), slot computation, write-back to the user's own calendar.
• Task extraction and breakdown through an LLM via function calling, structured output.

Flutter · Riverpod · Firebase · Vertex AI