“My job is really easy to tell but hard to do”

Accelerating algorithms with parallel and distributed computing

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By Veronika Früh

Simone Foderà just smiles when asked about Munich's self-proclaimed status as Italy's northernmost city. The computer scientist was born close to Rome and lived in Milan for many years during his studies. Winning the Munich Quantum Valley fellowship was what brought him to Munich, more precisely to the Chair for Theoretical Solid State Physics at the Ludwig-Maximilians-Universität München, where he is now doing his Ph.D. “I definitely do not feel like we are in Italy,” he states. But he does feel very welcome here. In fact, Munich was his first choice when he started looking for his options after his Master’s degree. “My Master’s thesis was about reinforcement learning and quantum computing,” he recalls, but in that moment, quantum computing felt closer to his heart. His research for scholarships or Ph.D. positions included many places in Europe and North America but he was also looking specifically for opportunities in Munich: “I just typed into google ‘quantum, Ph.D., Munich’ and found the Munich Quantum Valley fellowship,” Simone tells. The city just fascinated him when he was visiting on holidays some years ago. “When I discovered that I was accepted here in Munich, I stopped all of my research, because I was really lucky, happy, whatever, because this was my first choice. If I could have chosen whichever city in the world, I would have chosen Munich, probably.”

Simone describes himself as a very ambitious person. After his Computer Science degree from the Politecnico di Milano he thought intensely about his next step: “I had a tough choice because there were many good options, both in Milano and outside.” He didn’t like software engineering too much in his Bachelor but loved computational engineering. When he found out about the new Master’s program High Performance Computing (HPC) Engineering at his university, he was intrigued: “I was really fascinated but also a bit skeptical because I couldn’t have any type of reference, because nobody ever took that Master’s degree before, so it was a bit of a bet.” But for Simone, it was a perfect fit with a good mixture of informatics and mathematics, and really applied at the same time. The engineering approach is something that really suits him, as he explains: “Trying to solve problems by getting your hands dirty, trying to work with stuff where it is not completely clear how you should do that, is exactly my thing!”

And as if studying a brand-new Master’s program wasn’t challenging enough, Simone also took the chance of doing a double degree. “I was able to study HPC Engineering at the Politecnico di Milano and Computational Science at the Università della Svizzera italiana,” he tells. “Usually double-degree programs take three years, whereas this one was just two years long, which was really nice,” he continues. The plan was to study in Milan for the first year and move to Lugano, Switzerland, for the second year. But since the two cities are not that far from each other and most of the courses were available online due to Covid anyways, it was cheaper and more comfortable for Simone to follow the lectures from home and just travel to Switzerland for his exams. This actually granted Simone plenty of free time, as he says – which he didn’t spend idly: “I invested my time to start my Master’s thesis earlier.” In the end, he finished his degree in just three instead of four semesters and was the first person to graduate from this new program. “There was this whole ceremony just for me,” he recalls with a laugh. “That was a really cool experience. And something I am proud of.” When he started his Master, he didn’t know what to expect. For that reason, it makes him all the happier that today he gets lots of messages from bachelor students curious about the degree and to be this point of reference for them.

"I am really glad that my job has an immediate impact in the life of my colleagues"

It was during his Master that Simone understood for himself, that he really enjoyed doing research, navigating his own ideas, finding his path and concluded that starting a Ph.D. would be the right thing for him to do. “I find it most exciting to develop something new, which is a mixture of pure research and effectively coding at your computer,” he tells. Which is exactly what he is doing now. The scientist is working on an algorithm called quantics tensor cross interpolation (QTCI), a quantum inspired algorithm. It was developed by quantum theoretical physicists to tackle problems related to quantum many body physics. But it is not a quantum algorithm and Simone works with classical computers, not quantum computers. “This algorithm tries to approximate a function using smaller objects called tensors,” Simone explains. “If you have a function which is too big to be stored on your computer, you may try to apply QTCI to this function to see if you can find a tensor train, a union of tensors, to have a much smaller approximation of your original function,” he continues. Like this it is possible to create a good approximation of large functions by using a small amount of memory. What he finds both challenging and stimulating about working with QTCI is, that it is a heuristic algorithm: “It means, it is basically trial and error,” Simone explains. “You cannot know a priori if a certain function will be approximated well or badly by your algorithm.” There is the risk of being disappointed if it doesn’t work, but what Simone sees mostly are the endless opportunities the algorithm gives him to try out.

Simone Foderà, 24


Position

MQV doctoral fellow


Institute

LMU – Chair for Theoretical Solid State Physics


Degree

HPC Engineering, Computer Science


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Being on his computer is one of Simone's favourite things to do, whether it's for work or leisure.

But these are just the basics, Simone points out, just an algorithm used by his research group. “What I do exactly as a computer scientist, is to optimize and accelerate the algorithm”, he explains. For that, he uses parallel computing and distributed computing. “What parallel computing means is that one computer does multiple things at the same time by using different cores,” Simone breaks down the first concept. “And distributed computing is using many computers all at the same time to work together to achieve a result,” he adds. The computer scientist is really excited about the fact that he has access to distributed computing setups at the LMU or the Leibniz Supercomputing Centre as this is something he wouldn’t have if he was just working somewhere on his own. “My job is really easy to tell but hard to do,” he summarizes his work, “because there are plenty of problems which arise whenever you try to use distributed computing.” One of the challenges, for example, is managing the communication of the computers within the cluster. Since he is effectively using many different computers, he has to consider that they all have different memories and that the communication can be very slow. To design an efficient distributed computing algorithm Simone therefore tries to reduce the amount of communication to a minimum while still making them work together. “You have to find that trade-off which will then effectively enhance the speed of the algorithm that you are running,” he explains.

Finding new applications for the algorithm

But he is not only aiming to accelerate the algorithm: “My job is to make it as easy as possible for the user to use. So, my goal is to make my work as little an inconvenience as possible for other people.” In the end, he wants to build an option, that can just be switched on if needed, and the code works faster. Right now, his physics colleagues are already applying his acceleration to work on their problems, that can take multiple days to calculate. With Simone’s code, that duration can be reduced significantly. “I am really glad that my job has an immediate impact in the life of my colleagues and to whoever is using that library that we are building”, he says. There are still some problems with the compatibility of code, but the computer scientist is optimistic, that a seamless implementation that can be used by everybody will be ready really soon. While he is currently working at a theoretical physics chair, he is already thinking about possibilities to apply his QTCI algorithm also “outside of physics”.

As an engineer by training, Simone of course knows the basics in physics, but describes himself as far from understanding what his physics colleagues are actively doing. “But I realize that every person has their own understanding, their own knowledge”, he explains. Therefore, focusing on doing his own best work, adding his specialized skills to the overall project and building tools that help as many people as possible doing research in their respective fields is what he likes to do. One of the things that he loves most about being a computer scientist are the many different possibilities to apply what he is working on. “Right now, my plan is to try to apply QTCI to financial mathematics,” he describes an example for applications that lay outside the focus of his current research group. He has always been fascinated by that topic, as he tells, because he likes everything that is abstract, like math or coding. To explore the direction of financial mathematics further, he is already in contact with a professor from TU Munich. “The cool part about my Ph.D. is that if I come up with an idea at any point, I can definitely try it out without being scared of the consequences,” he states.

Facing and overcoming challenges

Simone grew up loving to play videogames and staying on his computer all day long. That he can now do exactly that in his job is something he really enjoys. “Of course, from an objective point of view, a sedentary life is bad,” he admits. “But I enjoy staying at the computer even for twelve hours a day. It is something that many people would not like. But for myself it’s a good experience.” He likes that his work does not require a lab, all he needs is his laptop. And since his job is not physically demanding, he has the energy to go to the gym and work out in his free time.

Balancing his work and his free time was actually something that the computer scientist had to learn when he started his Ph.D. When he moved to Munich, he spent many Saturdays at the office. “I feel that in Italy, especially in Milano, we tend to overwork a bit, whereas in Germany people take mental health and work-life-balance more seriously,” he draws a comparison. At the beginning he struggled a bit with re-organizing his week. After being initially shocked that everything is closed on Sundays, he now adjusted well to what he calls the German lifestyle: “After living in Germany for a while you start to understand that in Italy you waste your weekends doing chores, whereas here you know that when Sunday comes you are really free.” These days he doesn’t find himself regularly without food on Sundays anymore but can really enjoy the “cute” city of Munich and its many green areas.  

It was mostly the move to another country, away from his family, that challenged Simone at the beginning of his Ph.D.: “The culture is different, the language is different, it took me quite some time to get used to this new country”, he admits. “So, at the start, my job was not as efficient as it is now.” And, as it is true for most Ph.D. candidates, his first months were mostly about understanding what he is doing, knowing almost nothing beforehand about the algorithm he is now working on. But he quickly found his way into it. Today, roughly half a year later, he is feeling confident with his progress. “Of course, stress is part of the Ph.D.,” he says. “But in Milano we say that stress is the fuel for achieving something. So, whenever I feel stressed, I feel motivated to work,” he adds. Simone also finds great joy in the fact, that diving deep into particular topics and learning new things, something he always loved to do, is now actually a part of his job. “I will read this book and I will read that paper, but I know I am not wasting time, because it is part of the Ph.D. itself to study your topics and your arguments,” he summarizes this part of his work routine.

The one thing that the Ph.D. student does not particularly like regarding his academic work is writing it all up at the end. “Right now, what I am doing is technically hard. But I really enjoy this type of complexity, I find it really stimulating,” he explains. “Whereas a challenge that I faced during my Master’s thesis and I will surely face again during my Ph.D. is writing the thesis, writing a paper.” The computer scientist is so used to think in abstract categories and in terms of numbers or functions that he finds himself somewhat stuck when in comes to writing his results down. But, as with every other challenge that comes his way, Simone is looking forward to facing these difficulties and overcoming them. 
 

Published 29 August 2025; Interview  29 April 2025