- DP “National Railway Infrastructure Company”
- DP “Transport Construction and Restoration”
- “Electricity System Operator” EAD;
- Ruse Municipality
- Municipality of Varna
- Aksakovo Municipality
- Gorna Oryahovitsa Municipality
- Svilengrad Municipality
- Municipality of Dimitrovgrad
- Municipality of Sevlievo
- Lovech Municipality
- Municipality of Gabrovo
- Kazanlak Municipality
- Karnobat Municipality
- Suhindol Municipality
- Balchik Municipality
- Elena Municipality
- Trangeo Ltd.
- Eurotransproekt Ltd.
- Inotransproekt Ltd.
- Sofia Municipality
- Odesosstroi Ltd.
- “FRAFORT Twin Star Airport Management” AD
- DS “Air Traffic Management”
- “Devnya Cement” Ltd.
- “MTG Delfin” AD
- “ECANA” AD
- Territorial Directorate “State Reserve”
- “Maintaining of the Cleanliness of Marine Waters” AD
- Ministry of Youth and Sports
RUBICON ENGINEERING is one of the founders of the Bulgarian Association of Railway Construction Consultants, and from December 2016 to August 2018 the Executive Director Mr. Sevdalin Valnarov is Chairman of the Bulgarian Academy of Sciences.
“Danube Table Tennis Club”, Rousse
The men of Dunav Rousse are official champions for the 2015/2016 season in Group A – Northern Bulgaria. This gives them the right to participate in a Premier League jump in July against the team of Haskovo!
All matches of the team were viewed under the watchful eye of Mr. Sevdalin Valarnov – Director of Rubikon Engineering – a friend and benefactor of the club without whom the Danube could not have such a team!
Strategic Infrastructure and Investment 2015
General sponsor of the 10th annual conference “STRATEGIC INFRASTRUCTURE AND INVESTMENTS 2015, BULGARIA AND WESTERN BALKANS”
“All Bulgarian Saints” Temple
All Bulgarian Saints” Temple in the yard of the “Todor Kableshkov” University of Transport, Sofia
Supporting the publication of two separate books in Bulgarian and English
Support the publication of two separate books in Bulgarian and English at the anniversary edition “60 years of the Danube Bridge Ruse – Giurgevo” with an author’s team headed by Dipl. Eng. Ivan Gogev;
Supporting the publication of a book in Bulgarian at the anniversary edition “150 Years Rousse – Varna
Supporting the publication of a book in Bulgarian on the anniversary edition “150 Years Ruse Varna and 150 Years Railway Infrastructure in Bulgaria” with author’s team headed by Eng. Ivan Gogev /;