About us

SymbiOpen is an open source web development company based in Sofia, Bulgaria.


We are what was earlier called Shtrak. Some of our team have been meddling with web technologies since early 2000s, later spreading their expertise and studies across various grounds, such as software solutions with ASP.NET, Java EE, Microsoft Sharepoint, etc. In 2010 we took a turn to fully open-source oriented team, founding Shtrak as a web agency, providing services for WordPress and Drupal based web applications.

As bold as it might be to state that – we were the first folks to do an open WordPress and Drupal training course in Sofia, having it hosted by Sofia University. Following years we kept teaching WordPress in the local hackerspace. As much as we were recognized for our live courses and active contributions to the open source community, our efforts were targetted at helping various companies, individuals and non-profits in securing and growing their online presence.

By 2016 there were five of us in the team, working on 10 or sometimes even more projects at a time. WordPress custom web applications had become our focal point and we dropped completely Drupal support.

In the end of 2017 accumulated personal matters lead to the company being put on hold by it’s CEO and owner. Ongoing projects were completed before the spinning down of Shtrak, some of the employees were forwarded to work in partnering organizations and some started their own freelance career, continuing cooperation with most of our long-term clients at the time.

In March 2020, just when COVID pandemic hit Europe, Shtrak was revived under a new name – SymbiOpen. As the owner of the company remains the same and their expertise remained in the domain of the WordPress ecosystem, the company remains true to its love for open source technologies and thrive to do good businesses, non-profits and individuals online.


We are focused on solving business problems of small and medium sized enterprises through open source technologies, supporting our clients every step of the way.

Tech stack

Despite our love for open-sourced technologies, we don’t limit our team on what they use as their prime workspace. Still, our strengths lay upon the foundation of every-day usage of various Linux distributions, running local server environments with Apache2 and Nginx. Although we don’t provide Linux administration or maintenance services, we take pride in building up our own testing and development environment, keeping our reflexes for supporting our client environments, whenever a need for this occurs.

WordPress as a web platform and foundation for further web development is our basis for the projects that we build for our clients. Our IDE of choice is JetBrains’ PHPStorm which we insist on licensing for each of our employees.

Why does that matter to someone non-technical? By using well-known open source software, we set our clients free on the decision with whom they will be working in the future, avoiding vendor dependencies and bothering with licenses of proprietary software.