We organise various formats of popular science events, which gather between 100 and 800 guests. Some of our team’s members are scientists and engineers, while others are just science geeks and enthusiasts. But we are all volunteers who are passionate about science and believe in Ratio’s mission.

Liubomir Baburov

I have been fascinated by popular science since 2008. My interest in the field was awakened by the books of Richard Feynman and Richard Dawkins, which were also the impetus behind the establishment of the Ratio foundation back in 2012.

Nowadays, I am closely involved with the organisation of the NGO Evolutionary Look Association, and since 2018 I have had the luxury of focusing a bit more on our big events.

Meanwhile, my work experience is in the field of IT product management and business development. Since 2012 I have been serving as manager director of Ozone.bg.

Vassilena Valchanova

I have been actively exploring my interest in science and critical thinking since 2010. In 2012, I participated in the founding of Ratio. As a member of the NGO, I am in charge of promoting our events, establishing meaningful two-way communication with state and municipal institutions, and working with Ratio sponsors.

Outside of Ratio, I have over 10 years of work experience in the field of communications, marketing and PR. Over that period of time, I have taken on a variety of projects for different companies and participated in the organisation of a series of events with attendance from 100 to over 800 people.

Nikola Kerekov

I have been a part of organising Ratio since 2014. I am in charge of the selection of topics and the communication with speakers for almost all of the organisation’s events. I am also actively participating in programmes for international scientific exchanges, scientific congresses, conferences, and popular science events.

I hold a bachelor's degree in molecular biology and a master's degree in cell biology and pathology. I graduated with honours from Sofia University "St. Kliment Ohridski ”. At the end of 2015, I completed my PhD in immunology at the Institute of Microbiology at the Bulgarian Academy of Sciences.

I have 11 years of experience in research in the field of human autoimmunity, DNA vaccines, and the development of animal models of human diseases.

Petko Zhelyazov

I have been a part of the Ratio team since 2014, and in the last couple of years I have taken on the role of a host and moderator of our events.

I have studied several academic disciplines in the field of humanities and have a master's degree in european studies and international politics. My professional experience is in the field of corporate governance.

Most importantly, however, I am a proud husband, father of two children, and a passionate bibliophile.

Snezhana Yaneva

Since the beginning of 2018, I have been actively engaged with the promotion of the Ratio events and with the financial planning for the NGO. Besides pro-actively seeking new communication platforms, media outlets, and partners to reach audiences, I am also in charge of coordinating our volunteers.

I am in possession of a mathematics degree and a master's degree in finance, which I earned with honours from the University of National and World Economy (UNSS). My work experience is in the field of finance and marketing, and I am currently employed at Telenor as a market research analysts.

I have also had a book review blog in Bulgarian since 2016.

Dimitar Smilyanov

I have been a part of the Ratio organisation since 2015 and at this stage I am in charge of the technical support at our events.

Outside of Ratio, I work as a developer of web platforms and mobile applications, and I have previous experience in computer games development. Since 2017, I have also been a member of the Receipt Bank team.

Over the last 10 years, I have also been actively involved in organising events and volunteering for various organisations—OpenFest, RailsGirls Sofia, Begach.

Events and Lecturers

Mihaela Nikolova

More than a year ago, I attended a Ratio event about the stars and their life in our vast Universe. The lecturer and the topic grabbed my attention and interest so much that in an instance 2 hours have passed and from then on I am an extereme follower of Ratio. I have been in the team since May 2020, dealing with attracting and finding amazing, awe-inspiring speakers from all around the world. By profession and education I am a water supply and sewerage engineer and I feel that my work is my mission. In my spare time I go to rock concerts, climb mountains, read science fiction novels and ambitiously contribute to Ratio as a volunteer, which gives me great pleasure.

Ivan Dimitrov - IvanTheChemist

My name is Ivan, but a lot of people know me just as The Chemist. In Ratio I am involved in lecturer selection, presentation refinement (style and content), video recording and editing. In a sense, this is a transition from a similar volunteer position I have with Nakama (anime and manga) to more serious topics with larger impacts on society. I have graduated with a chemistry profile from NNMH, biology in Biological faculty of Sofia University, dropped out of a master's program in Bioinformatics in the Wageningen University and Reasearch Centre, and now I work as a QA Team Guide.

Radina Rasheva

I am Radi. I'm a lover of art, architecture, nature and (most of all) good people. I've been a Ratio fan for a long time and a volunteer - since the beginning of 2020. I work in the field of communications and I'm among the people who can happily say they enjoy and love what they do. My activities in the Ratio team are just as enjoyable. It's fascinating what a group of volunteers can do when they're curious about all things science and have a strong desire to share it with others.

Petar Dyankov

The first Ratio event that I attended was the autumn forum in 2019, in the Sofia Event center. I couldn't believe how professionally it was organized. The presenters were fascinating and covered extremely interesting topics, making them accessible to the public. From then on, i started following all of Ratio's events, and visiting all that i was able to. I joined as a volunteer in July 2020 to help the events and organizers team with inviting new lecturers. Aside from that, i work as a financial analyst for Coca Cola European Partners. I am a Certified Global Management Accountant, I have a BA in Business and Management at Aberystwyth University and a MA in Finance and Investment at LSBF. I also have a Facebook group aimed to help working students with their performance and recently published a course for efficient learning - The Ultimate Students’ Handbook on the Udemy platform.


Dana Tileva

I joined the Ratio team as a graphic designer in 2017. I am involved in the creation of the visual content for our small and big events alike, graphic facilitation during major events, and the production of all the press materials accompanying the work of the big R.

Outside of Ratio, I am a graphic designer at Receipt Bank, a graphic facilitator in 500 Markera, and a freelance designer. I am interested in calligraphy, animation, painting, and everything art related.

You can check out my stuff here https://dribble.com/ladeviant

Nevena Niagolova

Since 2018, I have had the honour of doing graphic art for Ratio. I am an artist and designer who has also embarked on the path of architecture. In my work, I use a variety of different techniques and mediums and am constantly striving to learn something new.

Outside of Ratio, I spend my time working as an intern architect at RED Studio and as a freelance graphic and web designer. I also devote time to making art, animation, and games, as well as participating in exhibitions.

My website is www.nevena.org and you can also find me on Instagram as @nevcheart.

Kremena Pehlivanova

Since the end of 2018, I help Ratio by eveloping some of our graphic design works. Professionally, I am a UI/UX designer. Over the last few years, I've mostly worked on studying, conceptualizing, prototyping, app usability tests in VR/AR, AI Chatbots and Voice Assistants, as well as mobile apps for iOS and Android. I also teach part time, on the subject of visual communication, as well as design everything from logos to book covers as a freelance designer.

Desislava Ivanova

I joined the design team in 2019. For a while, I worked as a graphic designer and recently I've started working on UI/UX.

I love travelling, learning about new cultures. I am also passionate about photography, fantasy, board games and cuisine.

Eleonora Svetozarova

I am a designer, a cook at home and a fan of popular science. A fan of space, NASA, science-fiction, and Tekla Alexieva's book covers. I have huge collection with patterned socks. Good movies, good food and good mood lovers. Working for Ratio is an inspiration for me.

Iva Kostova

The science fascinates and excites me. I respect every voluntary and selfless act and have always believed in the greated good of the human nature. I have been involved in freelance graphic design and have...


Michaela Yaneva

I split my time between project management, photography and digital marketing. Joined the Ratio team in 2015. An enthusiast with interests in various scientific fields, ranging from linguistics, biology and particle physics to the science of chocolate soufflé preparation. I believe in the power of education and that science must be communicated in an accessible way.

Boris Almishev

I have been working in the IT field for years, I love technology and еven more science - mostly in the field of hi-tech development, astrophysics and cosmology. I joined Ratio as a photographer back in 2018, around the time I was starting out with (professional?) photography. I believe that science is interesting, but very unpopular in Bulgaria, so I wanted to use whatever talent I have to change that. In my case - to capture the moments that make the Ratio events so great.

Nevena Rikova

I'm one of those lucky philologists having a day job in the publishing sector and loving it. Yet it doesn't seem to be quite enough, so I use every opportunity to indulge into photography, mess up with visual arts and strive to be a full-time good mother. I bumped into Ratio's enthusiasm and energy rather by chance but it turned out to be totally and inevitably contagious. I love science in all its forms and believe everyone (well, almost everyone perhaps) would do so, if it's presented to them in the right way. And that's what Ratio does. And I'm there to take the picture.

Teodora Georgieva

I joined the Ratio team in the beginning of 2019 year. Thanks to it I am meeting interesting people, learning a lot about science and most importantly - I am enjoying my time as a volunteer. Speaking about myself I am philanthropist with interest about running and hiking, travelling and exploring new cultures and meeting people. Other interests of mine are graphic design, marketing and event management, where I try to specialize into more professional level.

Antonia Yankova

Guided by my fear of missing out, I joined the Ratio team in 2018. Candid event photography has been part of my life since 2015, and ever since I can remember, I take interest in event planning. When I'm not behind the lens, I work in a multinational IT company and try really hard to graduate from university.

Vera Petkova

I am a professional photographer since 2003 and an unprofessional one for even longer. I also hold a BA in Photography. I love chaos, surprises, to experiment in the kitchen and to be amazed by beauty in the most unpredictable of places. Ratio has shown me a completely new and unexpected world which is also extremely exacting and fun


Svetlomir Zdravkov

I joined Ratio’s enterprise in 2018 when i was promised science and alcohol drinks (after then also food, mostly sweets) in exchange for content for the facebook page. This proved to be a very fruitful deal and very soon after that have been supplemented by editing and organizational work related to the content team. Currently I'm a PhD student in Sofia University in the department of sociology studying science and technology.

Kalina Fartunkova

I joined Ratio’s team in 2019. I’m in the content team, which means I create content for our Facebook page. During the events, I basically help however I can. My whole experience, working in Ratio’s team, has been an awesome adventure so far. Aside of that, I study Psychology at Sofia University. In general, I spend most of my time focused on my specialty – doing research, participating in workshops, etc. Moreover, I’m interested in any type of science which is why Ratio turned out to be a great opportunity. I’m keen on photography, literature, nature and I have a special thing for music. One of the reasons I study psychology is because I’m fascinated by people. That’s why I enjoy observing and studying them (not too intrusively, I hope…). Travelling is also a big love of mine – I like exploring different cultures and places.


After being secretly in love with Ratio for two years and regularly stalking them....uhm...pardon, visiting all their events, I finally became part of the copywriters team in 2019. Since then my responsibilities for the organisation have encompassed the writing, editing and proofreading of content, aimed at showing the world how awe-inspiring science is and provoking interest in it. Apart from that, in the last 7 years, I have been working as a journalist and am currently employed as a technology and foreign news editor in a European newspaper and its corresponding website. I would also say about myself that I am an insatiable philomath, a complete hodophile and a keen swing dancer. Most recently I have also developed a culinary passion, more specifically in the field of pastries and deserts making.

Nikolay Dyulgerov

I have been part of the Ratio team since the end of 2017. Currently, I'm working as a software developer. Apart from that, I like playing guitar, running, reading books, watching films, and listening to music. Occasionally, when I have time, I dabble in some translation.

Anzhela Dargova

I joined the Ratio team in the summer of 2018 as an editor (and sometimes content creator). I am a big fan of science fiction and fantasy. Due to this I have certain expectations for the future as a world where the advances in science and technology have turned fiction to reality. I have a degree in Psychology, Organizational Behavior and Consulting, currently stidying as post-graduate qualifcation Genetics and Biomedicine at Sofia University "St. Kliment Ohridski" and working in the field of clinical research.

Petya Stoyanova

It’s all about my love to astronomy that connects me to Ratio, 500 km away from Varna and the sea where I live. But it’s such an insignificant distance for the Universe scale and I happily joined the content team at the end of 2018. I always imagine myself as a scientist-astronomer in my dreams, but it happened to become a Master of Economics in the real life. Apart from my solid financial experience, I am also involved in a digital marketing adventure now. In addition to the night sky, I am also enthusiastic about the sea, rock music, my two children and the strong belief in science.

Snezhina Piskova

I came across Ratio completely by chance. I came back to Bulgaria after 4 long years of studying abroad and wanted to gain some experience as a copywriter. And suddenly BANG! a friend mentioned Ratio, I did my research and was hooked straight away. I’m not gonna lie, it was love at first sight - cool content, cool people, the full package. Besides Ratio, I work as a marketer in a startup, study Dutch, go to SoftUni every once in a while and go pole dancing every now and then (it’s not what it sounds like, I swear!)Other interests I have: drowning myself in books, taking photos, playing the ukulele, extreme sports and conquering new peaks (in every sense of the word)

Marina Ivanova

April 13, 2020 - I scrolled my facebook and what to see - RATIO is looking for marketing ninjas. I had recently completed an overall digital marketing course and I couldn't wait to use what I have learned, so I immediately wrote that I was FOR it. While rummaging through the other teams to see what interesting things were happening there, I came across the content team and an article that I really wanted to write. And so from one it became 2-3 and so to this day I don't stop writing, the coolest thing I've done lately (apart from all the other 100 stuffs I`m doing, because I can :) Science has always stressed me, I am even afraid of it, BUT with these cool people you can't do other but step out of your comfort zone and write something about thermonuclear fusion, for example. Outside of Ratio, I am a marketing specialist in an advertising agency, graduated in Bulgarian philology and love BOOKS, all kinds. I am passionate about travelling, workouts and finding secret untouched places in our beautiful country. I am very self-critical, hate to make mistakes but never give up and believe that everything is happening for a reson.

Mitko Mihalkov

During 2019 I had the unbelieveable chance to be in the right spot in the right time and the event was called Ratio: A Star Is Born. Since then little by little my interest towards this incredible project has been growing and the natural course of happenings for me was to transform from a spectator to a member of the team. Shortly after that I learned that this would be possible thanks to another person recently joined Ratio (A very special Thanks) and since May 2020 I help with useful and interesting accompanying information for Ratio's events. Apart from that, when I am not on my daily job I can be found in the park with my bicycle (during the summer), in the mountain skiing (during the winter) or playing board games with my friends.

Petya Vasileva

I have joined the RATIO’s team in 2019 and since then I am helping with advertising the events internationally. Currently I am working on a project, in collaboration with scientists from CERN, which is part of the PhD program that I am enrolled in. My interests lay in the field of programming and Big Data analysis. I love reading, sports and cooking. Science is an important part of my life and I strive to support any scientific initiatives.


Iavor Pachovski

I joined the Ratio team in 2018, I'm mainly responsible for the mixing and editing of the Ratio podcast. I'm a professional composer working with video games, trailers, movies and other media, although I've graduated a couple of Humanity disciplines. I strongly believe that bringing closer scienties and other people is the way to disarm superstitions, urban legends and fake news. This is my reason why I'm here.

Nikolay Boyadzhiev

I joined the Ratio team at the end of 2019 as part of the Technical Team. Along with my new venture as a volunteer, I get to meet cool people and learn super interesting things. I started my professional career in the IT field as a Project Manager. And since 2019 I have been working as a web application developer at Melon, where I am involved in a lot of fun projects. I like to travel and meet new people. Part of my other passions are extreme sports, video games and reading good books.

Ferdun Mestan

I am part of Ratio team since beginning of 2019. I joined because of friends that joined previously and here I find new ones. I work as SQA or in short as software tester. In my spare time I read, listen to music, play board and computer games. Also I love to travel to interesting places - made by humans or natural. I am a cat lover.

Simeon Kostadinov

I joined the Ratio team at the end of 2018 as part of the technical team. My primary responsibility as part of the technical team is to handle the streaming of our events, and other common technical activaties. I joined the Ratio team as a volunteer after I went to a few Ratio events, because I strongly believe that the work we are doing has a positive inpact on our society. On top of that as part of the Ratio team I have the opportunity and joy of meeting with our lectors, which are some of the best specialists from our country, as well as all over the world, which is a big perk for me personally. In my professional career I work in the IT sector as a SAP Application Specialist.

Volen Minkovski

I joined the Ratio Team in 2018 as a construction worker and then moved to the Tech team. As a part of the team I aquire new skills and apply some of the ones acquired at my job as a system administrator. My other interests are, enticing stories in any format (reading, playing or watching), road trips, and most of all understanding how things function and if possible taking them apart.

Julieta Atanasova

I like to learn something new every day, to challenge and improve myself. That's why I was very happy when in 2018 I had the opportunity to join the Ratio team. I am an economist, but I am professionally engaged in programming. I participate in the organization of the jPrime conference and I am a mentor at Rails Girls. I like to fill my free time with books, fitness, traveling, concerts and board games.

Georgi Batilov

I'm a member of the Ratio tech team since 2019. My higher education and most of my work experience are both in the field of light and multimedia design and technology. With my know how I'm able to contribute to the the technical team. From the first Ratio live event I stumbled upon, I was instantly hooked. I'm usually spending my free time between my loved ones, my dog and computer games.


Mariana Naidenova

I am a Software Developer since 2017, and my work in the field has taught me to seek new and different knowledge.I learned about Ratio from my friends, who were constanly sharing a various events on social media. So, out of pure curiosity, I was brought to a Ratio event and I realay enjoyed that experince. I volunteered in early 2019, again driven by the desire to try something different and learn something new. Since then, I've been helping mostly with the development of the website and the Ratio shop website. It is really interesting to see so many different people gathered together by one cause.

Karina Delcheva

Ratio swiftly became my favourite Bulgarian event the moment I stumbled upon it, two years back. The presentation of pop science within a casual atmosphere, rooted in an infiite curiosity about the world is probably the main reason I was instantly inspired to work with Ratio and help the organization keep up the great work they do! My work within Ratio is on maintaining the English version of the website. Professionaly, I am currently a junior frontend developer, but my past experience includes data analysis, managing a program for youth integration, humanitarian work.

Stanislav Atanasov

In fact I did go to the first Ratio becouse I liked the team and the idea ... Years later I'm doing the site and some IT stuff. Frivolous, ucivilised and as a whole I waonder why they put up with me ... but at least they know they can always depend on my help. Truth be told - not alway on time but always unfrivolous.