Tomislav Petrovic, Developer in Velika Gorica, Croatia
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Tomislav Petrovic

Verified Expert  in Engineering

Machine Learning Developer

Velika Gorica, Croatia
Toptal Member Since
January 23, 2018

Tomislav is a full-stack developer and systems architect with more than 15 years of experience designing and developing systems of all sizes as both a standalone freelancer and a member of a large team.



Preferred Environment

Git, Visual Studio Code (VS Code), Visual Studio

The most amazing...

...project I've worked on was designing and building an enterprise banking system from scratch.

Work Experience


2007 - PRESENT
  • Designed, developed, and implemented real-time monitoring system for Zagreb Stock Exchange.
  • Developed multiple iOS (Objective-C) and cross-platform (Xamarin) mobile games for various clients.
  • Developed Machine Learning projects for classification problems and financial predictions using Keras and Tensorflow.
  • Designed and developed a Machine Learning hardware sharing platform.
  • Worked on multiple smaller to middle sized projects ad architect and developer.
Technologies: React, Python, C#, SQL, .NET

Head of development

2001 - PRESENT
VIP Data
  • Led the development of enterprise IT systems in financial sector.
  • Managed a team of analysts and developers.
  • Successfully led multiple large migrations from legacy to new systems.
  • Developed and designed modules of enterprise products for travel industry.
  • Created and built document management systems.
Technologies: SQL, .NET

C3 Credit Card Management

I've managed the team that designed, developed, and implemented a credit card management system for Visa, MasterCard, and Diners Club brands currently in production in multiple financial institutions. The system completely covers all of the back and front office processes of a credit card company for both issuing and acquiring (card issuing, POS integrations, authorizations, transaction processing, payments, online banking, etc.) and integrates with a large number of third parties both as a service provider and user.

The system was developed using C# for the front-end (ASP.NET) and back-end systems (batch processing and real-time services) in addition to multiple SQL Server database servers.

eCommerce site using advanced algorithms to predict and ship products to subscribed customers. Built using React, Flask, and MySQL.


A web app connected to an NLG that generates real estate listings using user inputs. Built using React, Flask, and Postgres.

Shoppea Feed Concentrator

A system that reads data from multiple eCommerce feeds (Amazon, Awin, Admitad, etc.) and stores it in a MySQL database and Google BigQuery for further review. Built as a Flask app deployed to AWS EC2.


Web book reader that allows translation of the words or phrases using Google translation API. Built using React, Flask, and MySQL.

Printmates Dashboard

Photo printing kiosk management dashboard built using React (CoreUI), Flask, and MySQL.


A fitness program platform allowing coaches to define courses that users follow and complete defined tasks. Built using React, Flask, and Postgres, deployed in Docker containers.

Augmento AR App

iOS and Android AR application built for T-Mobile using Unity and EasyAR displaying a video for defined targets.


I served as the lead developer for the team that developed a tourist agency management system (booking, sales, finance) for the largest agency in Croatia that was later deployed to multiple other agencies and is still used today.

The system was developed as a Windows desktop application using C# with a central SQL Server database.


A platform that allows data scientists and Machine Learning enthusiasts to train their neural networks on other peoples hardware. Built using Flask for the REST API and React for the front-end. Keras and Tensorflow are used for neural network training.


Document management system for scanning, processing, archiving and retrieving large quantities of documentation, used in multiple financial institutions as well as some smaller companies. Built as a Windows desktop and web application using C# and SQL Server.

ZTM - Zagreb Stock Exchange Trading Monitor

A system for real-time monitoring of stock trading on Zagreb Stock Exchange. A multi-node distributed server with a custom load balancer that serves a large number of Windows desktop clients. Built using C# and SQL Server.

ML Ticketing Solution

A machine learning classifier that integrates with an existing ticketing system and automatically assigns IT support tickets to the best developer based on a model trained with previous assignments. Built using Flask and Tensorflow.

Looney Invaders

A cross-platform space invaders game for iOS and Android mobile phones. Built using Xamarin and CocosSharp framework.

Fruit Discovery

Application for tracking and planning processes in the agricultural industry. Built as a Windows application that works in both offline and connected mode with a central server.

Programming with Google Go Specialization



Deep Learning Specialization


JULY 2016 - JULY 2019

PCI Professional (PCIP)

PCI Security Standards Council




Microsoft Visual Studio, Xcode, PyCharm, Git, Visual SourceSafe, Visual Studio


Flask, .NET


SQL, C#, Python, Delphi, JavaScript, C, Objective-C, Swift, Go


Agile Software Development, REST, Waterfall Development


Windows, Xamarin, Visual Studio Code (VS Code), Linux, MacOS, AWS Lambda, AWS Elastic Beanstalk, Docker


SQL Server Management Studio (SSMS), Microsoft SQL Server, MySQL, SQLite, Amazon S3 (AWS S3), PostgreSQL


Machine Learning

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