Benjamin Mayrargue, C# Developer in Besançon, France
Benjamin Mayrargue

C# Developer in Besançon, France

Member since September 30, 2013
Benjamin is a highly motivated and self-driven Xamarin developer and a DevOps engineer with many years of experience. He prides himself on his ability to turn any idea into a good specification. Benjamin can create mobile apps, APIs, and back ends using C#, AWS, Blazor, Docker, Kubernetes, and Helm.
Benjamin is now available for hire


  • Freelance
    Training & Training Content Development, Training, Technical Architecture...
  • Metageek
    C, C++, USB, APIs, iOS, Android, C#, Xamarin
  • Airbus Helicopter
    Bluetooth, iPad, iOS, Xamarin, C#



Besançon, France



Preferred Environment

Kubernetes, Windows, Visual Studio Code, Visual Studio

The most amazing...

...people I've worked with are the ones who give me some consideration.


  • Developer

    2009 - PRESENT
    • Created Wi-Spy Air iOS/Android apps for a Toptal client. This enterprise-level tool analyzes the wifi low-level protocols for planning of wifi deployment and maintenance. It is connected to a backoffice through an API.
    • Built "Cosmo Moto" iOS and Android apps along with the microservices API server. The app works with a Bluetooth safety light for motocycles. It detects accidents or falls and automatically calls for emergency help and notifies your loved ones.
    • Developed Vfr Tracks iOS/Android apps. Vfr Tracks is a tracker for leisure planes. It can livestream the plane position and flight parameters and browse and display details of publicly-saved tracks and their pictures.
    • Programmed, a defunct NFC tag manager app for Android. The app automates actions based on the scanned wifi tag.
    • Created Radio, apps for iOS and Android, capable of playing most radio streams in the highest quality and using a second volume level slider for fine-tuned volume control for very quiet places, such as in bed.
    • Taught five-day Xamarin seminars in training centers (10 sessions in two years).
    • Created the application, including website, backoffice, and tools. Managed a team of four. I was the CTO of the company.
    • Helped developers in live sessions through ASP.NET Core discovery and real-world usage, OAuth2 real-world usage, code debugging, and other things.
    • Set up a production-grade Kubernetes cluster on bare metal and migrated .NET Core apps, including a Blazor app with a Seq log aggregator and Kibana server. Set up RBAC authentication using Azure AD, Nginx, and Let's Encrypt automatic TLS certificate creation and assignment.
    • Integrated (and migrated) Stripe billing to directly sell my own software components on
    Technologies: Training & Training Content Development, Training, Technical Architecture, iOS, Android, C++, .NET Core, Xamarin
  • Expert Mobile Developer

    2018 - 2019
    • Created two Air Viewer apps for iOS and Android, available in the stores.
    Technologies: C, C++, USB, APIs, iOS, Android, C#, Xamarin
  • Expert

    2018 - 2019
    Airbus Helicopter
    • Added BLE communication protocols to an existing Xamarin Forms app.
    Technologies: Bluetooth, iPad, iOS, Xamarin, C#
  • Expert Mobile Developer

    2017 - 2019
    Cosmo Connected
    • Created both Android and iOS apps, available in the store.
    Technologies: Location Tracking, Google Cloud, MySQL, .NET Core, C#, Xamarin
  • R&D Manager

    2008 - 2010
    • Led a research and development team that handled load testing, international billing, real-time web UI, migrations to ASP.NET MVC, and study of micro architecture.
    Technologies: Microsoft SQL Server, ASP.NET, C#
  • C# Developer

    2002 - 2008
    Telecom Italia
    • Worked on an internal search engine using COM objects.
    • Created a captive web search portal for kids.
    • Created and deployed a transcoding and distribution system of movie files for IPTV.
    Technologies: CSS, HTML, JavaScript, Microsoft SQL Server, ASP.NET


  • Mon geste en + Application

    I wanted to support the fight against the Covid-19 and my contribution was to lead the development of the Mon geste en + application, for a non-profit organization IFEP.
    My extra gesture application is developed to protect people around you and reduce the number of new cases, by recording daily the people with whom you have close contact. Additionally, I created my own app which can validate QR codes for the police forces. Both applications are open-sourced, to ensure security and privacy.

  • Vapolia

    I created Vapolia's website in 2008. using ASP.NET 4 and jQuery, which used to run inside a Windows virtual machine over KVM/Proxmox (a Linux/Debian host hypervisor) on a dedicated server on OVH Cloud. I set up and upgraded the whole cluster myself and now it runs inside Linux Docker image, containing the ASP.NET Core runtime, deployed in a Kubernetes cluster (on OVH Cloud) using a Helm script.

  • XamSvg

    I created a unique, affordable, and easy to use offline licensing system, a XamSvg plugin for the Xamarin SDK, that can save time and give more flexibility for both developers and customers.

    Earlier, with each increase of pixels per inch on mobile retina screens, developers had to create new images for each new resolution, increasing the workload and the application weight. But now with SVG vector graphics (which are describing an image mathematically through lines and curves) they can change their size and the resolution without any pixelization.

  • Vfr Tracks

    I developed leisure aviation Android and iOS mobile apps that can track the position and flight parameters of small aircrafts in real time using Xamarin Native. Within the apps, you can create your live stream maps that can be shared with your teams and followers. Both apps are available in English and French and feature an infinite smooth scrollable newsfeed style using an asynchronous pageable API which supports SignalR for live streams, push notifications, deep links, and background state management on all devices and OS versions (Android 5.0-10, iOS 10-13) and a Facebook-style loading state animation.

  • Wi-Spy Air

    An enterprise-level wifi network analysis tool dedicated to wifi planification and maintenance. It captures low-level wifi packets and frequency, using a scanner to create a map of your wifi network, compare it later for maintenance, and detect a lot of issues with wifi deployments.
    This app for Android/iOS uses an USB Wi-Spy Air device (plugged in the lightning port for iOS) and features a real-time update of all fields in all "opened" screens using a reactive software architecture, and correctly manages all the background states of any Android/iOS version.
    The apps are connected to a back end through an API. It features user registration and connection, enterprise level connection, reporting of wifi snapshots, and categorization in sites/rooms (autocompletion fields).
    The USB connection is managed by a C/C++ library.

  • Cosmo Moto

    Cosmo is the first connected safety brake light for motorcycles. I built the whole architecture for Android/iOS apps using Xamarin Native, secure and documented APIs in .NET Core for Linux/Debian on Google Cloud, MySQL schema and queries, and worker microservices plugged into the existing Drupal back end.
    The app communicates with the Cosmo device through Bluetooth LE. It features a strong light, intelligent crash detection, real-time GPS position reporting, fail-safe crash reporting to loved ones, and paid assistance. Technically both apps can update the device firmware.
    Applications also feature a real-time, offline voice command recognition in five languages using a C++ library. The firmware update stack for the BLE device is written in pure C#.
    The API back end has an OAuth2 client, a public API front, a MySQL database, scheduled tasks using Google Cloud PubSub, a private API, and it exchanges data with the eCommerce website.


    I made Android/iOS apps that configure NFC tags (small and cheap stickers that can be integrated into all sorts of products). After configuration, the tags will trigger actions when a phone is in their near field. For complex actions, the applications should be installed, but they don't have to run in the background, nor they require an internet connection. The apps feature easy UIs to read and write complex actions to any NFC tag, limited only by the memory available in the tag.
    The NFC stack is written in pure C#.

  • Airbus Helicopter

    Upgraded a large and technical iPad app written three years ago, dedicated to helicopter pilots, which registers specific flight parameters and is aimed at replacing the manually written flight reports.
    I designed and implemented Bluetooth LE communication to a private flight device to get more flight data.
    To propose changes and improve performance, I analyzed the exchanges between the app and the API server, which was a legacy ASP.NET web API and also upgraded parts of the web API to a new version. Additionally, I worked on the DevOps by setting up continuous integration and automatic build-in the cloud and I trained an Indian developer. The app itself had heavy technical debt, written in an old version of Xamarin.Forms, but now it uses the latest technologies, had many of its bugs and inconsistent behaviors fixed, and is much quicker to react to user actions.

  • Shapr Personal Networking

    I created the first versions of the Android/iOS mobile apps and in the next two years I was implementing the evolutions and various updates. I gave advice on app content and design, as well as support on design tools. I recruited, managed, and trained additional external developers to support the fluctuating workload.
    For this project, I used my own XamSvg component, full Xamirin C# platform-specific technology and I also integrated LinkedIn Connect, Facebook Analytics, Google Analytics, and AppsFlyer.
    Device-independent vector graphics dramatically reduced the time lost, by testing and fixing graphics on multiple devices.

  • Speaker at Mobile Conference at IBM Headquarters

    I spoke at the mobile conference, which was held at IBM’s headquarters in Paris in November, 2013. I demonstrated how to code Android/iOS apps using C# and how to reduce code duplication up to 80% by using a cross-platform library. Windows phone apps, Windows 8 store app, and Mac App store app were demonstrated, as well.

  • Radio

    Radio is an Android/iOS application, which can play most radio streams in their highest quality and has an exclusive second volume level slider for a fine tuning in very quiet places. It uses ExoPlayer on Android and on iOS the low-level audio subsystem and features customizable skins and a brushed UI.


  • Languages

    C#, SQL, C#.NET, C++, C, JavaScript, HTML, CSS
  • Frameworks

    .NET Core, JSON Web Tokens (JWT), .NET, Blazor, Windows Presentation Foundation (WPF), Razor Pages, ASP.NET
  • Libraries/APIs

    Xamarin.iOS, Xamarin.Android, Web API, PubSubJS
  • Tools

    Bitbucket, Git, Azure Active Directory B2C (ADB2C), Trello, Slack, WiX Installer, Helm, Visual Studio, RabbitMQ
  • Paradigms

    Concurrent Programming, Model View Controller (MVC), Design Patterns, Microservices Architecture
  • Platforms

    Xamarin, Azure, Kubernetes, Visual Studio Code, Windows, Android, iOS, Amazon Web Services (AWS)
  • Storage

    MySQL, SQL Server DBA, Google Cloud, Microsoft SQL Server
  • Other

    Crash Fixing, Xamarin.Forms, Internationalization, Cloud Infrastructure, MSMQ, Technical Architecture, Training, iPad, Bluetooth, APIs, USB, Location Tracking, Training & Training Content Development


  • Master's Degree in Artificial Intelligence
    1995 - 1995
    Jussieu University (Paris VI) - Paris, France
  • Master of Science Degree in General Engineering
    1990 - 1995
    Esme Sudria High School - Paris, France


  • AWS Practitioner
    MAY 2020 - PRESENT
  • ASP.NET Web Developer - Level 3
  • Visual Studio 2019 Expert
  • Querying Data with T-SQL Expert
  • Entity Framework Core Expert
  • C# Expert
  • Planning Microsoft Azure Solutions - Proficient
  • iOS Expert
  • iOS Publishing, Distribution, Deployment Expert
  • Android Expert
  • English Level C1
    JULY 2019 - PRESENT

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