Freelancer profile translated to English.
Back to original languageAbout Valentin
iOS developer for 8 years, I have worked on a variety of projects: a critical app for SNCF train drivers, a banking application for Banque des Territoires, and R&D projects in startups.
I am used to working alone with full project ownership as well as within structured teams of up to fifteen developers.
What matters to me in every mission is to deliver an application that lasts over time: fluid, reliable, and easy to evolve. Whether it's fixing a difficult-to-reproduce bug, adding a new feature, or taking over an existing codebase, I get involved in the project as if it were my own.
I am comfortable with demanding topics such as offline mode, security, or complex interfaces, but above all, what matters is that your app truly meets your users' needs.
Based in Lyon, I work remotely or on-site according to your needs, full-time or part-time.
Feel free to contact me to discuss your project.
French
Native or bilingual
English
Fluent
Can work on-site
Lyon (up to 10km), Lyon (up to 10km), Paris (up to 10km)
Experience
- SibeliantheiOS DeveloperCONSULTING AND AUDITSOctober 2025 - December 2025 (2 months)Lyon, France
Context
Complete Signal - is a mobile application that allows users to report wild waste on their route via a photo and GPS position.The application must allow reporting even when offline, with synchronization of routes and photos done automatically when the device reconnects to the internet.Missions
- Ownership & delivery: sole iOS developer, design and development from scratch to an internal pre-production build (R&D project, fluctuating team).- Architecture & DI: implementation of a Clean Architecture (UseCases, Repositories, Services, DTO/Mappers, Router) with dependency injection via RepositoryInjector (live/mock modes for dev & demo).- Offline-first & synchronization: local SwiftData persistence and background sync engine (NWPathMonitor + restart on startup), with retry state management for the next sync and internal logs (user-invisible sync).- Data consistency: local UUID + temporary offline ID; priority creation of the route during sync, then remapping of photos to the server ID to ensure photo ↔ route attachment (prevention of orphaned photos).- Media: photo capture, attempt JPEG conversion then fallback to imageData, application storage (not in gallery), REST upload and local purge after backend acknowledgment.- GPS & battery: optimized CoreLocation implementation.- Quality & testability: unit tests focused on UseCases and API calls, with mocking via protocols. - Banque des TerritoiresiOS DeveloperBANKING AND INSURANCEJanuary 2025 - September 2025 (8 months)Paris, France
Context
Mes comptes - Banque des Territoires is a mobile application that offers users management of their professional accounts and budgets.The application serves as an authentication and bank account management channel. It allows users to view accounts and transaction details, validate operations in real-time, and easily identify Banque des Territoires contacts.I worked with a small team on the finalization of the application.Missions
- Delivery & stabilization: implementation of features and corrective/evolutionary maintenance, with full responsibility for the iOS scope (dev, integration, fixes).- Authentication & security: implementation of biometrics (FaceID/TouchID depending on device) and an SMS OTP used for enrollment (account addition), login, and sensitive operations (operation validation). Management of biometric lockout cases and password fallback.- Account protection flow: lockout after 3 failed login attempts and implementation of an account unlocking flow.- Demo mode: creation of a demonstration mode based on mocked data, activatable at launch via a dedicated account or via the development environment (controlled by DI).- Product tracking: Matomo instrumentation (screen and action tracking) for usage monitoring.- Quality & testability: unit tests focused on UseCases with mocking via protocols.- Accessibility: VoiceOver improvements (accessible elements, focus order, announcements) following an audit. - SNCF ConnectiOS DeveloperTRAVEL AND TOURISMMarch 2022 - December 2024 (2 years and 9 months)Paris, France
Context
Sirius Next - is an iPad application for train drivers in various activities (TN, Voyages, TER, and Intercités) with strong constraints on security, readability during driving, and offline functionality. Integration of high-precision GPS with degraded case management (GPS loss).The application allows train drivers to prepare for their journeys and adopt a more economical driving style.Missions
- Organization & collaboration: evolution within a growing team (from 3 to 13 iOS developers, with backend/product/QA/lead). Systematic code reviews on each MR.- Documentary Management Module Referent: taking charge and development of a module for accessing business documents, with local storage and synchronization of new content.- Advanced PDF reading: integration of a PDF reader including search, highlighting, and error reporting functionality on documents.- Planning: implementation of a J-5 to J+30 schedule, visualization of missions, manual creation of unplanned missions, and representation of service periods that may span two days.- Preparation & driving: development of critical routes: validation of pre-filled information (equipment, Vmax...) then launching a driving screen with business-specific display (ideal position and speed graph, POI, work zones, upcoming stations/schedules information, ...).- Degraded GPS mode: implementation of fallback behavior in case of GPS absence/loss (simulation via pre-recorded routes, partial data masking, possibility of repositioning at stations).- Architecture & industrialization: MVVM + Clean architecture (repositories/DI), modularization via SPM;- Quality & delivery: ~80% test coverage on functional aspects (excluding UI). Integration into the delivery chain (Fastlane). Monitoring and diagnostics via Datadog.- Facilitation of various ceremonies (Retrospective, Sprint planning).
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Education
- Expert in Information TechnologiesEpitech2018