Marian Kostadinov, Developer in Vienna, Austria
Marian is available for hire
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Marian Kostadinov

Verified Expert  in Engineering

Software Developer

Vienna, Austria
Toptal Member Since
February 23, 2017

Marian is an experienced full-stack developer who has been working on web projects and applications since 2004. He wrote his first programs in 1993 and had been programming ever since. He graduated with a bachelor's degree in informatics, so he transformed his hobby into his profession.



Preferred Environment

Firefox, Git, Windows, PhpStorm

The most amazing... I've done was to design the architecture and build the foundations of complex web-based software aimed at car dealers.

Work Experience

Senior Software Engineer

2022 - PRESENT
  • Contributed to the areas of finance and accounting as well as general high-level application features.
  • Implemented new functionalities and supported existing features (bug fixing, refactoring, etc.).
  • Proposed and implemented architecture and workflow solutions that improved the overall product quality.
Technologies: PHP, JavaScript, MySQL, CI/CD Pipelines

Lead Web Developer

2013 - 2022
autoPro24 datenmanagement GmbH
  • Developed an especially customized PHP-based framework.
  • Created a custom JavaScript library that complements the PHP framework.
  • Implemented a market analysis tool and integrated it into the existing system.
  • Implemented data import and export engines that support over 20 data formats.
  • Introduced a reporting system that builds dynamic PDFs, Word, and Excel documents.
Technologies: MySQL, HTML, CSS, JavaScript, PHP

Full-stack Developer

2017 - 2017
Yields (via Toptal)
  • Created a REST service that delivers the website content and handles the update and the deletion of information.
  • Created an admin panel where the site owner can manage the content and the site structure.
  • Prepared the website based on the provided design files. This includes a responsive design for the mobile version.
  • Implemented the site in such a way that it works with old browsers (such as Internet Explorer) with almost no difference compared to the modern browsers.
  • Installed and configured the software on the virtual machine; using Apache, MySQL and PHP (PHP-FPM).
Technologies: REST, CSS, JavaScript, MySQL, PHP

Lead Web Developer

2010 - 2013
Media Pieces
  • Built a holiday apartment booking system.
  • Developed various company websites.
  • Laid out the foundations of a web-based software aimed at car dealers.
  • Built an interactive online configurator for window profiles, sills, doors, and accessories.
  • Developed a CRM area that manages offers, orders, deliveries, and payments.
Technologies: MySQL, HTML, CSS, JavaScript, PHP

Freelance Developer

2008 - 2013
LogicaSoft Solutions
  • Created a PHP and JavaScript framework.
  • Built a content management system.
  • Implemented a web-based program that builds reports and Excel sheets based on financial data, customer information, and government based statistics and reports.
Technologies: MySQL, HTML, CSS, JavaScript, PHP


2004 - 2012
Sofia University, ProPeople
  • Taught an elective course of PHP at Sofia University—the students learned the basics of the language. The course ended with an individual project for every student.
  • Taught an internal JavaScript course for PHP developers. It was intended to improve the JavaScript skills of the PHP developers in ProPeople.
  • Taught an Internal PHP courses for junior job candidates. All the candidates that passed the final exam were given a chance to start working for the company (ProPeople).
Technologies: JavaScript, PHP


2007 - 2010
  • Worked as a member of the VMware converter team (Web-UI).
  • Developed, as part of a team, a proprietary library: jsLib.
  • Provided support for a ColdFusion-based application.
Technologies: Adobe ColdFusion, Adobe Flex, JavaScript

Senior Web Developer

2006 - 2007
  • Worked as a member of the PHP development team.
  • Provided front-end and back-end development and support.
  • Researched new web technologies and solutions.
Technologies: MySQL, HTML, CSS, JavaScript, PHP

Web Developer

2006 - 2006
  • Created database designs.
  • Worked on AJAX-based development.
  • Produced HTML and CSS pixel-perfect presentations.
Technologies: MySQL, HTML, CSS, JavaScript, PHP


2004 - 2005
Tetrakom IR
  • Supported a Visual Basic application for a Swiss university.
  • Worked as a member of the team that developed the first version of the PRIME system for NATO.
  • Acted as the main developer of a C#-based warehouse management system.
Technologies: XSLT, XML, Visual Basic, C#, Java


I prepared a simple demo game called Moomoo that became Bulls and Cows. It contains PHP and JavaScript code that can be explored. There are several places where a simplified solution is used to reduce the demo's volume.

The server-side code handles the player that generates a four-digit number with no repeating digits and the request router. The client-side code handles the player that guesses the number. Once the start button is clicked, the client will call the server until the correct number is guessed correctly. It usually needs about five guesses.


autoPro24 is a web-based application aimed at car dealers.
The dealers can manage their stock—purchase and sale information, invoicing, offers, availability, pricing, market analysis, customer management, activities, B2B, and more.

The application can import data from different sources using different import interfaces and it can also export the vehicles to various online platforms for car selling.

An interactive online configurator for window profiles, sills, doors, and accessories.

The users can choose the models, materials and accessories, set the desired dimensions and see the calculated prices immediately. Alongside there is a real time drawing of the configured objects.

The visitors add the items to their shopping cart and build an offer themselves. All shopping cart items and the contact data are then accessible and editable by the employees of the company.

The administrative area provides a full control of the site content but it also manages the full process—offers, orders, deliveries, logistics, installation, invoicing, payments, and more.

Bent Fishing
Bent Fishing is website where the users can browse and search for fishing-related items. The shopping cart can be transformed into an order.

The administrators are responsible for handling the incoming orders. Additionally, they can manage the products along with their pricing, availability and delivery information.

This system manages the orders, supplies, sales and transfers between the stores and the warehouses.

Sofia Public Transport - Schedules

A website that presents the schedules of all public transport lines in the capital of Bulgaria: Sofia. It is a part of the infrastructure of the public transport operations in Sofia.

The visitors can choose a line and see the schedule for every stop across the route, or choose a stop and see the schedules of all lines that stop there.

Additionally, it is possible to find all the direct connections between two stops and see a combined schedule of all lines that connect the stops.

The administrators can manage the existing lines, stops, routes, and import the schedules from the GPS data provider.


HTML, PHP 7, ECMAScript (ES6), HTML5, CSS3, CSS, JavaScript, PHP, XML, Java, C#, Visual Basic, XSLT, Curl Language, Bash Script, XPath


Vanilla JS, PHPUnit, Adobe Flex


JSON API, REST APIs, Asynchronous Module Definition, PHPMailer, Raphaël, Stripe API, JSON-RPC, PhantomJS, jQuery, PHPOffice (formerly PHPExcel), Node.js


Chrome Developer Tools, Apache, Navicat, Notepad++, wkhtmltopdf, Eclipse IDE, PhpMyAdmin, WinSCP, PuTTY, Xdebug, Git, Adobe ColdFusion, PhpStorm, Skype, cURL Command Line Tool, Slack, NPM


Object-oriented Programming (OOP), Object-relational Mapping (ORM), REST, Microservices Architecture, B2C, Functional Programming, Logic Programming, B2B, Unit Testing


Firefox, Apache2, Eclipse, Windows, Linux


MySQL, JSON, Relational Databases, Memcached, InnoDB, HTML5 Web Storage, SQLite, XML Parsing, PostgreSQL


PHP 8, Dynamic Websites, Software Architecture, Architecture, Full-stack, Psalm, Customer Relationship Management (CRM), Regular Expressions, Content Management Systems (CMS), CSV File Processing, Server-side PDF Generation, Cars, Git GUI, GUI Development, Transactions, CSS3 Animation, Infection PHP, Shopping Carts, Image Processing, WebSockets, SOAP, User Experience (UX), CommonJS, SVG, Validation, Storage, SSH, SFTP, CI/CD Pipelines

Industry Expertise


2000 - 2004

Bachelor's Degree in Informatics

Sofia University - Sofia, Bulgaria