Short Autobiography

I was born into a middle-class family in Heraklion, Crete, in December 1946. My childhood was carefree in an environment that gave me a lot of love without restricting my choices.

Ever since I can remember, I have been curious and persistent by nature. I asked questions about natural phenomena and machines that went largely unanswered by my parents. I was also relatively lonely with few companions. My first contact with school was somewhat difficult, especially in the first two years of elementary school. I tried to be a good student, but it sometimes caused me distress to sit at the desk for hours at a time.

I loved nature, especially the sea, and sought every opportunity to be near it. The village where my father came from in southern Crete and where my grandparents lived, was a particular attraction for me. It was a place of escape and freedom close to nature that I loved to explore with passion. The rivers, the plants, the animals and of course the people, shepherds and farmers.

This village had something else unique. It was built next to the ruins of Gortyna , one of the most important cities of ancient Crete, which flourished for 20 centuries, since Minoan antiquity. For some reason from a very young age, I felt an unspeakable magic visiting the ruins. I tried to decipher the inscriptions in Ancient Greek and was fascinated by the history of Antiquity. I wanted to be an archaeologist. From then on and for the rest of my life I had a very special relationship with ancient Greece and especially with the Greek language, history and philosophy that remains strong to this day.

In my studies I was quite good without trying to be first. When I was 16 years old, I passed the entrance exams to the School of Electrical Engineering of the National_Technical_University_of_Athens. The studies there went smoothly, but I found that the courses, except for a few, were not theoretical enough. I liked mathematics and physics and less so the applications. When I got my electrical engineering degree, I decided to start my postgraduate studies abroad in nuclear physics and so I found myself in Grenoble, France in August 1970. How and why is another story.

After two months of study, my encounter with a computer turned out to be fateful. I decided to follow another path: start studying Computer Science, much to the surprise of my friends and family, who considered the decision to be sheer madness. It was difficult to explain to them in Greek what it was all about. As a CS student, I was fortunate to have the support of Jean Kuntzmann, a brilliant mathematics professor, the Director of IMAG Institute, who became my mentor in the early years of my career. I owe him a lot.

In 1976, chance and my difficult character led me to change the course of my research. I was not happy with my work in a hardware research group for VLSI testing. I found it boring, not exciting enough, and decided to radically change direction. I applied to become a researcher in the Programming Languages Group. I was accepted with a lot of reservations, because my initial training was in electrical engineering and I was not considered good enough to do research on the group’s subject.

The period 1976-1982 was the most productive of my life. I quickly became interested in the semantics of languages and formal methods. It was a time when we were trying to develop mathematical foundations for Computing that would allow us to build computers and software in the same way that we build bridges. Program verification was a very hot topic at the time. Dijkstra’s and  Hoare‘s axiomatic theories, which were dominant at the time. I got the idea for Model Checking by trying to verify protocols. It all happened very quickly. In July 1979, I defended my These d’Etat on Le contrôle des systèmes asynchrones: concepts, propriétés, analyse statique, which laid the foundation of the method. A member of the jury found the theory nice but unworkable – “there are no programs with a finite number of states”, he said.

Between 1982 and 1992, I worked hard with my team, to apply Model Checking theory to protocol verification, as part of projects funded by France Telecom. We concentrated on solving the state explosion problem, in particular by developing tools. At the same time, a community around Model Checking and the use of temporal logic began to form, including Ed Clarke, Allen Emerson, Amir Pnueli, and myself. We shared a vision of verification that was very different from the then dominant axiomatic method. In July 1979, I organised a workshop in Grenoble on the “Verification of Finite-state Systems”. It was a great success and the following year we created the Computer_Aided_Verification Conference.

The success of our team’s results in the field of verification and formal methods has led to numerous industrial collaborations. In 1993, I set up the Verimag laboratory, an industrial laboratory under contract with Verilog, a Toulouse-based company close to Airbus. During these four years, Verimag transferred numerous results, the best known of which is the Lustre language currently used in the Scade suite, widely used for the development of critical avionics applications. After this period, Verimag became a public laboratory that I directed until 2007.

During the last decade of the last century, I became interested in the design of embedded systems, with research ranging from real-time system verification to scheduling and modelling. My research interests shifted progressively towards systems design. I completely left verification. I was passionate about system design because it requires multiple skills and mastery of a large number of topics ranging from requirements formalization, to software engineering, compilation, operating systems, and hardware. 

Since 2002, I worked hard with my team to develop the BIP framework for component-based modelling, motivated by my idea of correctness construction, where system architectures play an important role. Although this work is not as widely recognised as my work on verification, I consider it to be an equally important technical contribution and an important milestone in my achievement as a researcher.

2008 marks a turning point in my life. The 2007 Turing Award went to Ed Clarke, Allen Emerson and myself. This recognition opened up new horizons for me. For a while, I was in the limelight and the doors of academies and learned societies were open to me. At the same time, I had to tell the general public about my achievements and the importance of my discipline. A very gratifying task, but one that also involved my responsibility to the community I was supposed to represent. It was the start of a long and thoughtful process that led me to write a book I have published in 2022, Understanding and Changing the World .

In November 2009, Amir Pnueli, a long-standing friend and mentor, suddenly disappeared. I first met Amir in 1982 at a workshop on System Verification in Cambridge. Since then, he has had a considerable influence on my career and I owe a large part of what I am to him. 

In 2011, under French law, I reached retirement age, so I had to leave my post as CNRS Research Director and become an emeritus researcher. I find this regulation on compulsory retirement completely absurd. Even more than 10 years later, I still feel fit and passionate about my research projects. The opportunity to remain active was immediately offered to me by EPFL, where I accepted a professorship for the period 2011-2016. I have very fond memories of an academic life where I had the means to do research without chasing contracts and to set up a high-performance research laboratory.

It would be a serious omission not to mention my relationship with my homeland, Greece, with which I have always had very strong ties. I have already explained the extent to which Greek antiquity, its history, language and philosophy have fascinated me since I was a child. When I lived in France, I spent a lot of time studying ancient Greek, the origin of words, as well as their evolution over the centuries. Since my youth, my love of Greek language has led me to write verse, which is a relaxing exercise for me. I have published two collections of poetry with Armos Editions, and I continue to write for pleasure.

Since 2016, I have had the privilege of living a very creative life as a free researcher. I can choose my collaborations and publish as I please without being obsessed by my publication index. I have research projects around autonomous systems including fundamental and applied aspects. Of course, I closely follow the impressive developments in AI because, unlike the proponents of AGI, I consider autonomous systems to be the ultimate stage in the development of AI. 

When it comes to the future and the role of AI, I have a very different view from the dominant one. I believe that the AI revolution is still in its infancy and that we still have a long way to go before we have human-level intelligent systems. I think that the current hype, fuelled by the media and Big Tech, could have a detrimental effect on the development of the discipline, not only because of the disenchantment that could ensue, but also because of the push towards technical directions that favour gigantism and a dangerous slide from rationalism to empiricism. 

To conclude, I will say that I have been very lucky in my life to experience first-hand this great adventure that is computer science and its applications. I am amazed by what human intelligence can achieve, and I hope that the use of AI will enable us to go even further in our quest to understand the world and ourselves.

Joseph Sifakis, November 16, 2024.