
Benjamin Mayrargue
Verified Expert in Engineering
C# Developer
Besançon, France
Toptal member since September 30, 2013
Benjamin is a senior developer with extensive experience, given the number of years he's been working in the industry. He invests in startups and ideas, reviews customer projects, designs specs, audits codes, and creates ops manageable code. Benjamin also works on mobile app UI, 3D math calculations, APIs, and back ends—all using C#, AWS, Blazor, Docker, Kubernetes, and Helm.
Portfolio
Experience
- C# - 13 years
- SQL - 10 years
- Xamarin - 7 years
- Azure - 4 years
- Google Cloud - 3 years
- Amazon Web Services (AWS) - 3 years
- .NET Core - 3 years
- Microservices Architecture - 2 years
Availability
Preferred Environment
Windows, Visual Studio, JetBrains Rider, LoRaWAN
The most amazing...
...and interesting thing I'm running is a Helium LoRaWAN network with onboarded devices, earning crypto tokens on the Solana blockchain.
Work Experience
Developer
Freelance
- Created Wi-Spy Air iOS/Android apps for a Toptal client. This enterprise-level tool analyzes the low-level protocols for planning wifi deployment and maintenance. It is connected to a back office 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 motorcycles. It detects accidents or falls, 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 live stream the plane position and flight parameters and browse and display details of publicly saved tracks and their pictures.
- Programmed Tagzi.me, 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 tranquil places, such as in a bed.
- Taught 5-day Xamarin seminars in training centers (10 sessions in two years).
- Created the Dealdeouf.com application, including the website, back office, 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, OAuth 2 real-world usage, code debugging, and other things.
- Set up a bare metal Kubernetes cluster to host custom apps, including dotnet apps. Also, set up a Kubernetes on Azure to host SEQ.
- Integrated and migrated Stripe billing to sell my own software components on Vapolia.eu directly.
[Hourly] Experienced C#/Xamarin/.NET Developer To Update Mobile App
Aronetics LLC
- Upgraded a xamarin app to maui, modernized its UI, and fixed functional bugs.
- Communicated with the customer to understand its business targets and requirements.
- Automated the mobile app publication in stores with fastlane.
- Handled the publications to the Google Play Store, making sure the app pass validation and is publicly available. Fixed all issues with the store.
Expert Mobile Developer
Metageek
- Created two Air Viewer apps from scratch for iOS and Android, available in the stores.
- Built a real time reactive data acquisition engine that receives data from a hardware usb device and push them to active views, making all visible data in the app actual at any moment without the need of a manual refresh.
- Built many specialized and animated graphics and vizualizations to display acquired data: a Wifi spectrum congestion view, a Wifi signals intensity view, a wifi list view, ...
Expert
Airbus Helicopter
- Added BLE communication protocols to an existing large Xamarin Forms iPad app.
- Fixed the app's abysmal slownes by analyzing the causes and testing solutions, including a more robust architecture, and SQL query optimizations.
- Debugged the BLE communication protocol with the real world device. Used advanced technics to find out and squash bugs because of differences between the doc and the real software.
Expert Mobile Developer
Cosmo Connected
- Created both Android and iOS apps from scratch, available in the stores.
- Worked with the product manager to build the initial product UX.
- Worked directly with the hardware device partner to get the best reliability rate from the bluetooth device.
- Managed the publication of the apps in the stores.
R&D Manager
Betclic
- 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.
- Developed and implemented the load testing system at the Microsoft Lab in Paris.
- Worked with the database architects to improve the resilience and speed of the whole system.
C# Developer
Telecom Italia
- Worked on an internal search engine using COM objects.
- Created a captive web search portal dedicated to kids.
- Created and deployed a transcoding and distribution system of movie files for IPTV.
Experience
Mon geste en + Application
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
https://vapolia.euXamSvg
https://github.com/softlion/XamSvg-SamplesEarlier, 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
Wi-Spy Air
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
https://cosmoconnected.comThe 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.
Tagzi.me
The NFC stack is written in pure C#.
Airbus Helicopter
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
https://shapr.co/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 Appdays.fr Mobile Conference at IBM Headquarters
Radio
Woundzoom mobile Apps
• Developed the 3D wound detection and acquisition algorithms and the test bench system.
• Created the release build pipelines, linked the bug reporting service, and set up and linked the REST API instant log server.
Education
Master's Degree in Artificial Intelligence
Sorbonne University - Paris, France
Master of Science Degree in General Engineering
ESME Sudria - Paris, France
Certifications
AWS Practitioner
AWS
ASP.NET Web Developer - Level 3
Pluralsight
Visual Studio 2019 Expert
Pluralsight
Querying Data with T-SQL Expert
Pluralsight
Entity Framework Core Expert
Pluralsight
C# Expert
Pluralsight
Planning Microsoft Azure Solutions - Proficient
Pluralsight
iOS Expert
Pluralsight
iOS Publishing, Distribution, Deployment Expert
Pluralsight
Android Expert
Pluralsight
English Level C1
QIOZ (CECRL)
Skills
Libraries/APIs
Web API, PubSubJS, REST APIs, API Development, OpenCV, React
Tools
Bitbucket, Git, Azure Active Directory B2C (ADB2C), Trello, Slack, Wix Installer, Helm, Visual Studio, RabbitMQ, JetBrains Rider, Azure Monitor
Languages
JavaScript, C#, SQL, C#.NET, C++, C, HTML, CSS, Swift
Frameworks
.NET Core, JSON Web Tokens (JWT), .NET, Blazor, Windows Presentation Foundation (WPF), Razor Pages, ASP.NET, .NET MAUI, ARKit
Paradigms
Concurrent Programming, Model View Controller (MVC), Design Patterns, Microservices Architecture
Platforms
Xamarin, Azure, Azure Functions, Amazon Web Services (AWS), Kubernetes, Visual Studio Code (VS Code), Windows, Android, iOS, Google Cloud Platform (GCP), ARCore
Storage
MySQL, SQL Server DBA, JSON, Google Cloud, Azure Cosmos DB, Microsoft SQL Server
Other
APIs, Crash Fixing, Xamarin.Forms, WebSockets, Mobile App Development, Social Media Apps, Authentication, seq, Software Engineering, Migration, Internationalization, Cloud Infrastructure, MSMQ, Graphics Processing Unit (GPU), Serverless, CTO, Leadership, Technical Leadership, Architecture, Technical Architecture, Training, iPad, Bluetooth, USB, Location Tracking, Training & Training Content Development, LoRaWAN, Artificial Intelligence (AI), Mobile Apps, Emgu CV, SfM Systems
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