Hi! My name is Iordan!

I'm the CTO at Corpy&Co. in Tokyo, Japan. I would describe myself as a mixture of Software Engineer and Applied Mathematician. Some people have called me a reasonably good cook. No one has called me funny (yet). My main duties are to provide snacks and comfort for my colleagues.

Lately my interests focus on Explainable AI and Quality-Assurable AI. These past months I've been working with my colleagues on CONFIDE, our amazing (naturally) tool to introduce Explainable and Quality-Assurable AI to manufacturing companies. We have great plans for CONFIDE, so stay tuned, the demo will be live soon! I wrote an article about it, feel free to have a look.

I have a Ph.D. in Computer Science from the University of Lorraine, Nancy, France. I was member of the research team GAMBLE for three years, and I worked with Monique Teillaud on the subject Delaunay triangulations of a family of symmetric hyperbolic surfaces in practice. Sounds quite serious, I know. I will only say that one of the people who established Hyperbolic Geometry was warned by his own father that it would drive him crazy, and there is a lettuce involved. I won't spoil any more than that.

The algorithm that we proposed with Monique is implemented in C++ and is open source. It was inspired by CGAL, the largest open-source library for computational geometry. Our implementation is now proudly a part of the library. While working on my PhD, I participated in the ASTONISHING associate team and in the SoS ANR project.

What keeps me busy?

Mahatma Gandhi said that whatever we do in life is insignificant, but it is important that we do it. You might be thinking, yes, but Oscar Wilde said that quotation is a serviceable substitute for wit. The irony is not lost on me, but there you have it. Anyway, here you can see what I'm working on these days, and also some older stuff.

Work experience (at least the one I can put on my CV)

July 2019 ~ present: Corpy&Co., CTO

I moved to Japan in July 2019 and started my work at Corpy as Chief Scientist. I was promoted to CTO in April 2022. My duties are mainly to handle projects and the people working on them, to give advice, direction, and counseling (in multiple senses).

Until now, I've worked on projects for Toyota, AISIN, AIST, Ishida, Nikon, Ryoki, GS Yuasa, and many more. However, the most exciting and long-lasting one for me personally is CONFIDE, our own in-house XAI and QAAI solution. The motivation behind CONFIDE can be summarized in the following tweet.

CONFIDE is a tool that gives practical understanding and ease of use to companies that want to use AI in their manufacturing process. What is more, it implements Quality Assurance for AI, which is something still lacking from many other commercial solutions. This is one of the main reasons why companies are hesitant to adopt AI -- how can they trust something that works as a black box? We're working on solving that.

One step at a time, we are building CONFIDE and along with it our understanding of AI and related techniques. Once we are confident in our CONFIDE (ha!), we plan to expand our services to other, more challenging domains.

February 2019 ~ June 2019: Gamestream Srl., R&D Engineer

Gamestream is a gem hidden in Ludres, in the Lorraine region of France. The company offers game streaming services -- you can play AAA games on your smartphone, cheap laptop, or TV, even on your toaster (if it can run the right software). The only thing you need is a good Internet connection, a gamepad, and the necessary software. I have mentioned the software twice because that's what I worked on, so it's important.

In my time with the company, I developed a client for a Samsung TV, so that people could play games on it effortlessly, in Full HD at 60fps. That was a game-changer (second ha!) for hotels and hospitals. I was particularly touched by the motivation of Ivan, the CEO of the company, who wanted to install this software in hospitals to make a positive difference in people's lives. It was a privilege to contribute to this project and to learn so many things from the many talented people at Gamestream.

Oh, and the barbecue! Every once in a while, we would just have barbecue for lunch. Can you picture that? Freshly cooked meat, a cold beer, French countryside -- such nice memories!

January 2016 ~ March 2019: University of Lorraine, Ph.D. Candidate

Does this really count as work experience? I would say so, I think I worked during these three years.

During my thesis I had the opportunity to collaborate with some extraordinary researchers, crushing my own confidence and self-esteem in the process. In parallel, the occasional anxiety attack would manifest, so I guess the experience was quite unique and formative. They say that whatever doesn't kill you, makes you stronger, right? Right?!

Aside from that, I had the chance to go to Australia, to collaborate closely with researchers from Groningen and Luxembourg, and, of course, to include my work in CGAL. This is something that I'm actually proud of, if I may say so myself.

January 2015 ~ September 2015: IACM-FORTH, Graduate Research Assistant

The Institute for Applied and Computational Mathematics at the Foundation for Research and Technology Hellas is quite a mouthful, if not anything else. It is one of the major research institutions in Greece, and I had the luck to work there during my Master's thesis. Luck and persistence, I should say -- you see, needing money to survive is a very strong motivation to work and study at the same time.

In my time at IACM, I was surprised to learn that the little knowledge that I have can find applications in practice and save human lives. I worked with an extraordinary Post-doctoral researcher, Eleni Metaxa, who taught me so many things about hemodynamics (the way in which blood flows through veins). After many struggles, we managed to publish a scientific paper, my first publication ever! That was a truly great experience, with all its ups and downs.

May 2013 ~ June 2014: 01S Community Company, Software developer

Ah yes, my first full-time programming job! Such a great experience with the people from 01S! With them, I learned this insanely powerful tool called InstantDeveloper, and I had to re-implement the calculation engine for the Italian 730 tax declaration. The result? I blocked over 2000 operators on a national level for a whole morning. That was the first time I cried at work. Ah, fun times!

01S was and still is one of the best professional experiences I have ever had. Not only for all the things that I learned and for the projects to which I had the chance to contribute, but mainly for the people that I met and still respect until today. I still remember the food parties that we used to have whenever someone would have their birthday. And, oh my goodness, the porchetta that Daniele brought one day -- that was exquisite!

I'm telling you, unforgettable moments!

December 2009 ~ June 2012: Nanosoft, Software developer

This was the first time that I was actually paid to write code. Such an amazing feeling. Out of nowhere, my High School teacher, who had his own business, approached me and offered me to work with him. In my time with them, I worked on Windows and Windows CE devices (the palmtops, for those who remember). This is when I really got deep into programming and I also started playing around with Android applications.

I guess one can say that my teacher taught me in more than one ways. I would not be here, today, without the experience I got with him. Both on the development side, and on the business side -- he would always tell me that the user doesn't really know what they want, and, surprise surprise, 10 years later I'm finding myself remembering his words very vividly.

July 2007 ~ October 2009: Erbamea Srl., Warehouse manager

I couldn't skip mentioning my experience at Erbamea because it taught be so many things. I became an expert in medicinal plants and I could literally smell the bad from the good stuff. We were not only packaging herbal products from all over the world, but we were also cultivating and collecting local products as well. The comany has now grows beyond recognition, but I'm very happy that I could be there during the initial stage.

In Erbamea I was given a responsibility that I never had before, so this sense of owning my mistakes was developed to a considerable degree. More than that, I realized just how motivating it is to do my best when my work is appreciated, and this has had a very big impact on how I treat my colleagues today. Erbamea is a solid the stepping stone for me, and for that I am forever grateful. I keep only the fondest memories of my colleagues there, and especially Fausto, also known as Dr. Mearelli, the chess enthusiast who could talk about plants for hours with growing excitement.

What have I learned so far?

Here is a list of the milestones in my education. You can find links to the fruits of my labor in there, feel free to explore the material. If you have critiques, that would be nice. If you don't, that would be even nicer.
January 2016 ~ March 2019: Ph.D. in Computer Science, University of Lorraine

The topic of my Ph.D. lies in the domain of Computational Geometry. You can have a look if you want, but I warn you, it's quite technical. I was drawn to this topic mainly because of its strong practical component -- it was planned from the beginning that the resulting code would be a part of CGAL, and this was extremely exciting for me. The experience that I gained from this process is unique, having the chance to work with so many bright people is quite enlightening.

Aside from that, I learned French, I collaborated with people from different backgrounds on something completely new for me, and I failed multiple times. I want to believe that I have learned through this experience, and hopefully my work will help someone else do something even nicer. One can only hope, right?

September 2014 ~ December 2015: M.Sc. in Applied and Computational Mathematics, University of Crete

I actually left my job at 01S to go back to Greece and continue my studies. During the entry interview, one of the examiners thought I was joking, they couldn't believe I actually did that. But I did, and I would do it again.

The reason for me returning to Greece for my Master's studies is that I wanted to work with Prof. Karavelas, with whom I also worked during my Bachelor's thesis. I was inspired by him and wanted to continue in the same line of work, which ultimately led to my Ph.D. so I would definitely do it all over.

For my Master's thesis, I worked on something that I find very interesting -- cubic splines on the sphere! The splines that we worked with include a "tension" parameter and by varying this parameter, the spline becomes more or less smooth. The goal is to find the optimal parameters such that the shape defined by control points is preserved by the spline. There's a whole discussion on this, the manuscript is here. If you're up to it, you can also play around with the code.

September 2005 ~ March 2013: B.Sc. in Applied Mathematics, University of Crete

Right, that was a long one. The thing is, I interrupted my studies from 2007 to 2009, that's when I switched countries and was working at Erbamea. There was a family emergency that I needed to take care of, so I needed that time off. Looks bad on résumés, but family comes first.

When I started my studies, I was feeling quite disappointed because I always wanted to be a programmer. I felt like I would miss out on so many things, studying Applied Math instead. Well, it turns out that I was bitterly mistaken -- there's actually a lot of coding, and it's actually not just mindless coding, there is a lot of thought behind it. I feel like this has given me a unique perspective not only on problems and solutions, but on life itself. It might also be the reason why I'm overthinking everything, but that's a discussion for my therapist. Note taken.

It was not obligatory at my University to submit a thesis at the Bachelor level, but I wanted to do it anyway, it sounded like a fun final project. It was one of the best decisions I've ever made. I had the chance to work with Prof. Karavelas on a topic that was ultimately related to my Ph.D. Funny how life does that, right? Anyway, the thesis is here, but I must say that I myself cringe when I read it now, it feels so badly written... so please excuse undergraduate me.

And here is a list of the events that I have attended, either as a speaker or as a listener. Why am I giving you this list? Well... why not? It's not like I have anything better to do, right?
Speaker -- the events where I have given a presentation myself
9th International Conference on Curves and Surfaces (CS 2018)
Palais des Congrès, Arcachon, France, Jun 28 -- Jul 4, 2018
presentation slides (pdf)
CGAL Developers Meeting
INRIA - LORIA, Nancy, France, Mar 13 -- 16, 2018
presentation slides (pdf)
Journées de Géométrie Algorithmique (JGA 2017)
Centre Paul Langevin, Aussois, France, Dec 10 -- 15, 2017
presentation slides (pdf)
Astonishing Workshop
INRIA - LORIA, Nancy, France, Sep 25 -- 26, 2017
presentation slides (pdf)
33rd International Symposium on Computational Geometry (SoCG 2017)
The University of Queensland, Brisbane, Australia, Jul 4 -- 7, 2017
presentation slides (pdf)
Listener -- the events where I was doing my best to understand what's going on
SoS kickoff meeting
INRIA - LORIA, Nancy, France, May 3 -- 4, 2018
Geometry and Topology in Contemporary Material Science
The Niels Bohr Institute, Copenhagen, Denmark, Sep 3 -- 9, 2017
Workshop: Algorithms for the Medial Axis
The University of Queensland, Brisbane, Australia, Jul 7, 2017
Workshop on Practical Methods for Solving Computational Geometry Problems
The University of Queensland, Brisbane, Australia, Jul 6, 2017
Workshop: Geometric Aspects of Materials Science
The University of Queensland, Brisbane, Australia, Jul 4 -- 5, 2017
Graphs and Surfaces: Algorithms, Combinatorics and Topology
CIRM, Marseille, France, May 9 –- 13, 2016
Wave propagation in complex media and applications
ACMAC, Heraklion, Greece, May 7 –- 11, 2012
Neither -- these are the events at which we got some actual work done
CGAL Developers meeting
INRIA, Sophia Antipolis, France, Sep 3 -- 7, 2018
Visit to Gert Vegter
Johann Bernoulli Institute for Mathematics and Computer Science, University of Groningen, The Netherlands, Apr 9 -- 20, 2018
Partially supported by the University of Groningen and by the ASTONISHING associate team
Visit to Gert Vegter
Johann Bernoulli Institute for Mathematics and Computer Science, University of Groningen, The Netherlands, Jan 15 -- 26, 2018
Partially supported by the University of Groningen and by the ASTONISHING associate team
UR en mathèmatiques, University of Luxembourg, Luxembourg, Mar 29 -- 31, 2017
Partially supported by the University of Luxembourg and the ASTONISHING associate team
Visit to Gert Vegter
Johann Bernoulli Institute for Mathematics and Computer Science, University of Groningen, The Netherlands, Sep 19 -- 23, 2016
Partially supported by the University of Groningen and by the ASTONISHING associate team
Extended visit to Jean-Marc Schlenker
Mathematics Research Unit, University of Luxembourg, Luxembourg, Jun 1 -– 30, 2016
Partially supported by the University of Luxembourg and the ASTONISHING associate team
Mathematics Research Unit, University of Luxembourg, Luxembourg, Feb 18, 2016
Partially supported by the University of Luxembourg and the ASTONISHING associate team

What else would you like to know?

I've saved this space for all the random things that I think are interesting. Have a look around, and if you like something, feel free to keep it. I've also included some random info in there. It's random, there's a lot of randomness here. Chance? Hardly.
Dear Lordan, ...

STOP. Please stop for a second, and consider this -- why would I write my own name with a lowercase letter? Right, it's IORDAN, or iordan if you prefer. Sorry for the confusion, I went with the writing in my passport (although I do think that the Yordan version looks a bit weird so I'm quite happy with Iordan).

Am I Bulgarian?

I get that a lot. The answer is yes and no.

I was born in Bulgaria, my parents also, I have a Bulgarian nationality, for all intents and purposes I am a Bulgarian national. However, I belong to a tribe called Boyash. We have many names -- Ludari, Rudari, Linguri...

We are a nomadic tribe that would survive either by performing (think like street performers), or by making and selling utensils from wood and other natural sources (spoons, brooms, these large wooden bath tubs even). I myself am an expert broom-maker and broom-salesperson.

We have our own language derived from Latin (perhaps Romanian?) and mixed with some elements from Bulgarian. I guess because we live in Bulgaria. Our language doesn't have a written form, but we do speak it actively within my family. What I find fascinating is that I've found Linguri people in Greece, in Italy, and in France, and I can kind of understand what they say. Mind-blowing, really.

How many languages do I speak?

Another one I get quite often.

Let's count, shall we?

English, Greek, Italian, French, Bulgarian. That's 5. I also speak my own language (see previous item), which is not official, so I don't count that one. As for Japanese, I can only communicate basic stuff, so that one doesn't really count either. Therefore, 5.

I really need to work on my Japanese.

How to spend your free time if you LOVE solving problems?

We're talking about mathematical and/or programming problems, of course. These are easy to solve, the other ones are more complicated.

So if you're looking for a way to spend your free time, you can head over to Project Euler and have a look at the very large set of problems they have. Some of them are quite frustrating, but they will keep you busy, for sure. Have fun!

So how does Hyperbolic Space look like?

It's hard to imagine how Hyperbolic Space works. It's mind-bending, really. Fortunately, there are some very smart people like Vi Hart, Andrea Hawksley, Elisabetta Matsumoto, and Henry Segerman who have done something very cool for us common folks.

These people have created a Virtual Reality model of 3D hyperbolic space, and you can try it our in your browser right now. Try it out if you click here, and you can see the paper here. Once you open the window, you can use the W,A,S,D keys on your keyboard, or the arrows to navigate; use E,Q to rotate. It's like a game!

If you're up to it, you can also try the product of a 2D hyperbolic space and a 1D Euclidean space. It can cause vertigo. Yes, I know this is not how vertigo works, but trust me, in VR it can actually cause vertigo. Here is the paper, if you want to see how it works.

Have you ever wondered how Bézier curves work in hyperbolic space?

I did. Since I worked with these wonderful curves during my Master's, I wanted to see how they would work in the hyperbolic plane. So I made a simple widget on GeoGebra when I was playing around in my free time.

You can play around with the widget directly in your browser on this link. The implementation uses De Casteljau's algorithm, but it's implemented using circular arcs instead of linear segments (since, you know, in the Poincaré disk model geodesics are arcs of circles).

How does trust evolve? Hmm??

At some point I came upon this super cool interactive animation based on Game Theory (one of the fanciest things of the past few years, for some reason) that shows how trust evolves. If you've got a few minutes to play around, go for it!

Have you heard about the Game of Life?

John Horton Conway was an English mathematician who had the inspiration for this simple, but extremely powerful idea. He modeled the way a system of cells would behave with four simple rules. Wikipedia can tell you more about this.

I thought it would be a nice way to spend a weekend afternoon, so I made a tiny implementation in JavaScript. Since I was working with periodic things at the time, I made it so that the left-right and top-bottom boundaries are "glued" together (at least in the code). That makes it into a flat torus! You can see the page here. If you refresh the page, you'll get a new board! ;)

Trolley problem. Thoughts? Morality?

MIT's Moral Machine is an incredible project that will put you in crisis mode within two clicks. The idea is that you get to choose who lives and who does.

You see, everyone (well, at least some people, I guess) is thinking about the future when we will have self-driving cars. The thing is, no one thinks about what would happen if we actually got them. These cars will not exist in a vacuum, so it is highly probable that situations will arise in which a human life will be lost, no matter what the car chooses. The question then becomes, who should die, and who should live?

This is a version of the trolley problem, and it becomes highly relevant in the context of self-driving cars. This is what the Moral Machine does -- it makes you decide the fate of people and animals in such situations. Very thought-provoking, might cause some soul-searching.

Should we talk?

If you're still here and actually want to get in touch, I am impressed!
Please reach out and I will get back to you as soon as possible.
Iordan Iordanov
CTO, Corpy&Co.
4-4-11 Hongo, Bunkyo-ku
〒113-0033 Tokyo, Japan
iordan@corpy.co.jp