Antonio Seric, Developer in Split, Croatia
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Antonio Seric

Verified Expert  in Engineering

Xamarin.Forms Developer

Split, Croatia
Toptal Member Since
May 5, 2016

Antonio is a senior software developer with experience in developing all kinds of applications (web, desktop, mobile, and IoT) in the C# .NET framework, Antonio also has developed Android and iOS applications in C# (Xamarin). He works equally well on his own and in small/large teams to help you with your project from ideation to production. In his free time, Antonio researches new technology and perfecting his current ones.


C#, C#.NET, Microsoft SQL Server, ASP.NET, Azure, Azure SQL, Xamarin...
Azure, Xamarin, Android, .NET, C#, C#.NET, Microsoft SQL Server, ASP.NET...
SQL, Assembler, C, C#, C#.NET, Microsoft SQL Server, ASP.NET




Preferred Environment

Xamarin, Windows, Azure, Git, Visual Studio, C#, .NET MAUI, Azure DevOps

The most amazing...

...thing I've coded is a whole business solution in C#, from web application (front end and back end), workers to mobile application and IoT embedded device.

Work Experience

Software Architect | Developer

2017 - 2024
  • Migrated web applications on Azure along with the microservice architecture and AKS.
  • Implemented CI/CD using GitLab, Jenkins, and Azure.
  • Built a C#-based web application using MVC or the Angular framework.
  • Installed a mono-console microservices on the Ubuntu server.
  • Implemented Xamarin Forms for an Android and iOS application.
  • Implemented Xamarin native binding for Android and iOS library.
  • Set up DevOps pipelines using templates for reusing on multiple projects. Used infrastructure as code IaC ARM and Bicep templates.
Technologies: C#, C#.NET, Microsoft SQL Server, ASP.NET, Azure, Azure SQL, Xamarin, Visual Studio, Azure Kubernetes Service (AKS), DevOps Engineer, Azure DevOps, CI/CD Pipelines, .NET, Amazon Web Services (AWS), Bicep, Infrastructure as Code (IaC), REST, SOAP, Sonar, SonarQube, Security, Azure Active Directory B2C (ADB2C), Azure Administrator, Microsoft Entra ID, OAuth 2, Keycloak, Opal, Microservices Architecture, Microservices, Docker, Back-end, Industrial IT, Industrial Equipment, Hardware, React, TypeScript

Owner | Developer

2013 - 2018
  • Customized an Android tablet launcher with navigation specifically built for curriculum use for the teachers and students in a primary school.
  • Created an Android application generator service using C# and application templates in Android Java.
  • Managed the continuous integration and deployment of an ASP.NET MVC 5 application to test safety valves.
  • Created a reusable template library for the ASP.NET MVC 5 application with authentication and DAL and an Android library client for connecting to a web API.
  • Built a simple torrent client using MonoTorrent in Windows Forms.
  • Developed a web scraper with states for downloading files from sites.
  • Created an IE BHO extension to inject JavaScript into any site.
Technologies: Azure, Xamarin, Android, .NET, C#, C#.NET, Microsoft SQL Server, ASP.NET, ASP.NET MVC 5

Student Developer

2008 - 2014
  • Created a data logger device and server to collect information about the intensity levels of solar radiation and temperature.
  • Developed a converter RS232 to DALI in ATMEL assembler.
  • Created a hotel-booking system for the hotel's internal use.
  • Built a control-to-step motor with a microcontroller PIC over ethernet.
  • Developed Arduino controllers for two propellers to stabilize a simulating drone.
  • Worked as a professor assistant for projecting digital systems using Verilog.
Technologies: SQL, Assembler, C, C#, C#.NET, Microsoft SQL Server, ASP.NET

Software Developer

2011 - 2013
IT Sistemi
  • Distributed an extensive system with two different databases: four desktop clients and two web clients.
  • Gathered and sorted banking account information from a large database.
  • Created a dynamic report engine that generates RDLC.
  • Supported multipage TIFF documents for a scanning document management application.
  • Developed an Android app to check SVN changes.
  • Built an Android app that connects to a CMIS protocol for document management.
Technologies: Reporting, T-SQL (Transact-SQL), .NET, C#, C#.NET, Push Notifications, Microsoft SQL Server, ASP.NET, Windows GDI+

Take Remote Photos with Your Mobile
• Mobile apps (iOS, Android)
• Server microservice architecture (photo column)
• Azure services

• The mobile apps were built with Xamarin.Forms.
• Gstreamer was used for live previewing and was built with the Android NDK and SDK, which were also used in the Xamarin project.
• The photo column software controlled the camera and sends environment and power data to Azure.
• It also provided camera access (live preview and photo taking) to mobile clients.
• Various Azure cloud services were used: Azure IoT Hub, Azure SQL Database, Azure Web Apps, and Azure Blob Storage.

Modern Solution for an Old DOS App

Built a REST API service to communicate with a DOS app written in Pascal so that reading and writing files on the file system could be done.

The Android app is now a modern client for placing orders on a Bluetooth printer. It is built in with Android SDK Java.

High-traffic Web App

An ASP.NET MVC 5 web app built with ASP.NET MVC and tested with VSTS web test with 20,000 concurrent users trying to buy tickets.

The app is meant to sell popular tickets for events. It is a web app using SQL store procedures to optimize concurrency buying tickets with timeouts.

Mobile Social Network

This project involved Xamarin Forms apps (Android and iOS) and a full custom design. REST was used for the Web API and ASP.NET MVC for the back end for administrators.

The mobile app was a web client; some parts are also shown in WebView. The mobile app was also optimized to upload large files to the server.

Xamarin Components
These open source components for Xamarin are a collection of open source components (including bindings and plugins). It was created for native mobile platforms, Android and iOS, to be usable in Xamarin as binding libraries.
2004 - 2010

Master's Degree in Computer Engeneering

University of Split, Faculty of Electrical Engineering, Mechanical Engineering, and Naval Architecture | FESB - Split, Croatia


Software Architecture Training Program

Global Dev Experts


Programming in C#



Xamarin.iOS, Xamarin.Android, LINQ, Facebook API, jQuery, Windows GDI+, Square API, React


Microsoft Visual Studio, Git, Azure DevOps Services, Visual Studio 2019, Azure IoT Suite, Android NDK, Jenkins, MSBuild, GitLab, Subversion (SVN), Android Studio, VisualSVN, Trello, Visual Studio, GitLab CI/CD, WebView, Azure Kubernetes Service (AKS), Android Jetpack, Sonar, SonarQube, Azure Active Directory B2C (ADB2C), Keycloak


ASP.NET Web API, ASP.NET MVC 5, ASP.NET, Android SDK, .NET Core, ASP.NET Core, .NET, .NET Micro, Mono, ASP.NET MVC 6, .NET MAUI, OAuth 2


XAML, C#, C#.NET, C, JavaScript, T-SQL (Transact-SQL), YAML, Assembler, SQL, CSS, Opal, TypeScript


Desktop App Development, Web Application Architecture, Azure DevOps, Unit Testing, Design Patterns, DevOps, REST, Load Testing, Microservices Architecture, Microservices


Windows, Xamarin, Ubuntu Linux, Windows Server, BlackBerry, iOS, Azure, Android, Android TV, Azure Functions, Azure IaaS, Amazon Web Services (AWS), Docker


Azure Websites, Microsoft SQL Server, Azure SQL, Azure Blobs, SQLite, MySQL, SQL Stored Procedures, Cache, Microsoft Entra ID


Xamarin Studio, Xamarin.Forms, Push Notifications, .NET 6, API Integration, Back-end, Performance Optimization, Ubuntu Server, DNS, IIS, Internet of Things (IoT), Server Administration, Mobile Apps, Industrial IT, Hardware, Reporting, Android Wearables, Azure WebJobs, System Architecture, Architecture, Optimization, Content Delivery Networks (CDN), DevOps Engineer, CI/CD Pipelines, Bicep, Infrastructure as Code (IaC), SOAP, Square, Security, Azure Administrator, Industrial Equipment

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