Stefanos Petrakis, Developer in Safnern, Switzerland
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Stefanos Petrakis

Verified Expert  in Engineering

Web Programming Developer

Safnern, Switzerland
Toptal Member Since
January 26, 2021

Stefanos is an experienced developer who has programmed with PHP, Symfony, and primarily Drupal for more than a decade. His background in computer science, cognitive psychology, and computational linguistics allows him to work inside web technologies in a most versatile and innovative way. Freelancing using open source technologies feeds his soul as much as his desire to solve difficult problems for others using his unique skillset.



Preferred Environment

Lando, Visual Studio Code (VS Code), BunsenLabs Linux

The most amazing...

...thing I have built is a TTS system for Greek that generates natural-sounding Greek speech that is actively used by a number of navigation system vendors.

Work Experience

Senior Symfony Developer

2018 - PRESENT
ISS AG, Integrated Scientific Services
  • Defined, documented, and developed the next version of PEDeDose, the pediatric dosage calculation tool supporting medical professionals.
  • Supervised bug fixing, implemented new features, and supported users of existing installations of REGULA, the regulatory affairs software for medical devices and IVD.
  • Challenged and introduced new ideas for the use of internal tools for the development team.
Technologies: Katalon Studio, Bootstrap, MariaDB, Docker, Symfony 3, Drupal, Symphony, PHP

LingWare Engineer

2008 - 2021
SVOX (acquired by Nuance)
  • Supervised and managed the development of the Greek version of SVOX's core product, LingWare, a state-of-the-art text-to-speech system.
  • Programmed the phonological and morphosyntactic grammars required for providing a natural sound to the generated speech.
  • Searched, located, and on-boarded the voice talent that provided the recorded voice data needed by the system.
Technologies: Computational Linguistics, PHP

Senior Drupal Developer

2017 - 2018
  • Joined an agile project team with a very tight deadline and factored into successful and timely delivery of the project; the relaunch of
  • Provided support for recruiting new developers by assisting the management in the technical interviews.
  • Provided critical feedback and ideas for improving the Agile project management processes.
Technologies:, Drupal 8, Drupal, PHP

Technical Lead/Web Developer

2012 - 2016
  • Served as the technical project manager for the biggest company account (, providing almost exclusively to the development, deployment, support, and project management of the account.
  • Pitched and acquired a huge client (, providing an overwhelmingly convincing understanding of the client's needs and requirements.
  • Recruited and mentored more than two remote developers that have been in the company for more than seven years, proving that their selection and onboarding was perfectly thought through and executed.
  • Drove the small company of three into substantial growth as well as a very clear increase in revenue and reputation. It has become a financially secure company with more than five developers, as well as a few project and sales managers.
Technologies: Cost Estimation, Code Deployment, Server Administration, Contao, PHP 5, Drupal 6, Drupal 7, Drupal, PHP

Entity Translation Core Maintainer

An extension to Drupal 7 that allows field-based translation, a project that would turn out to be highly influential to the upcoming Drupal 8 and 9 versions, having most of its design and ideas integrated into the core Drupal distribution. Albeit not being the initial contributor to this project, I stepped in a couple of years ago to ensure its quality by increasing its test coverage and allowing its first major release.
2003 - 2007

Master's Degree in Cognitive Sciences

University of Athens - Athens, Greece

1997 - 2003

Bachelor's Degree in Computer Science

University of Piraeus - Piraeus, Greece


Acquia Certified Developer - Drupal 8



Zend Certified Engineer



Lando, Katalon Studio, Contao


SimpleTest, Symfony 3, Bootstrap, PHPUnit


PHP 5, Bash, PHP, Prolog, Lisp


Object-oriented Programming (OOP)


Drupal 8, Drupal 7, Docker, Visual Studio Code (VS Code), Drupal,, Drupal 6


Relational Databases, MariaDB


BunsenLabs Linux, Web Programming, Server Administration, Code Deployment, Cost Estimation, Symphony, Cognitive Psychology, Computational Linguistics

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