Stefan Jeschke is in the unique position of having left IST Austria and at the same time not having left the campus. He works now for Nvidia. Although the company which designs graphic processing units is based in Santa Clara California, Stefan Jeschke has rented an office on the IST Austria campus and works from there mainly communicating via skype and email with his colleges from all over the world. In an interview with Daniela Klammer and Kathrin Pauser he answered some interesting questions about his work.
Watch a short version of the interview here on youtube or read the long version below!
What’s written on your business card?
Stefan Jeschke, researcher at Nvidia.
What’s your job description?
Basically what I am doing is basic research, like I did at IST, I am working on realtime algorithms for future computer games.
What’s the cool thing about your job?
I am very free in what I am doing, as long as it is exciting and interesting for my managers. Whenever I find something that excites me I can work on it as long as I want or until something cool comes out. I am very free at choosing my time to work, where I work and how I work. We have a very international community at nvidia. I am basically working with people from New Zealand, from Bangkok, all around the world and the US of course. It is an interesting environment to work.
Do you travel a lot?
No, it is all skype meetings and online.
Where do you see yourself in the future?
Hopefully in the same job, if this works out. This is basically my dream job, I would say and I have no intent to change anything soon.
What’s your academic background?
I have a classic academic career bachelor and master computer science, computer graphics in my case. Then I did a PhD in 2005, followed by quite a few postdocs in different universities: TU Vienna, Arizona State university in Phoenix, Arizona, then TU Vienna again and then IST until last year.
What role did IST play in your career?
I learned a lot of new stuff here. The guy I was working with was Chris Wojtan he does physics simulations and I didn’t do that before too much. So I learned a lot from that perspective. He also introduced me to the job I have now. He made the connection for me so that was a very positive influence. I am still working with him quite a lot. So overall it is a very positive influence.
How was this step away from IST to your current job?
It was only like twenty steps, literally[laughs]my current office is only twenty meters away from my old office. Also was not such a big step because I still work in the same area I am still doing basic research as I did before. So in my case the difference is not that big but that might be very unique. I also have publications at the same conferences as before. I tend to pressure myself to publicize while my manager is more interested in demos for GTC but of course he also likes publications.
Can you give three pieces of advice to current IST members?
One advice is what worked out for me I didn’t think too much of a career to do but rather what I liked to do which was not too hard because in Austria all the contracts are short term anyways. Doing that what you like most at the moment is probably the best strategy to keep a healthy relationship to your job. Basically I never thought too much about long term because there are no long term perspectives for postdocs or similar positions in Austria. Just keep your focus on what you are doing now and do your best and go from there.
What is your favorite, funniest, best memory of IST?
This is a hard question. I enjoyed the photography club we always had nice meetings. That’s one thing. Of course the scientific rewards are another, doing really great work and having great papers accepted at the best conferences – that is certainly something that I remember.
What motivated you to choose IST Austria?
I had been at IST for some of the lectures and I think it was my wife that said, why don’t you apply there. What I liked is that there are only few students but those students are highly motivated and I liked that. That was one of the reasons to choose IST.
Would you say that your job is typical or unique for a computer scientist?
I would say it is pretty unique. As far as I know, I am the only employee in Austria at nvidia and that was quite a struggle to get that but now I can work from where I want within Austria.
- Photography (hobby),
- Road and Mountain biking (and daily bikes to work),
- Long-distance running
Johannes Reiter was a PhD student in the Chatterjee group at IST Austria, and is currently doing a postdoc in Prof. Martin Nowak’s group at the Program for Evolutionary Dynamics at Harvard University.
Hania Koever, Head of the Graduate School Office, interviewed Johannes in Harvard to find out about the journey that took him there.
What made you come to IST Austria?
I followed it in the news when IST Austria was opened, the first time was when they announced an IST Lecture with Martin Nowak. I found out more about IST Austria and at the end of 2009 I decided to apply for IST and do science there.
In his IST Lecture, Martin Nowak talked about game theory and in particular the prisoner’s dilemma; it’s a simple game where you can either cooperate or defect, and he could explain so many things in evolution just with that easy game.
What were you studying?
I studied Computer Science and just started with my master’s degree, and so I thought, that’s an advantage, you don’t even need a master’s degree—you can directly apply in the first year—this is my big chance. I came for interviews and was already very happy that I was invited.
Do you remember how big the group was that came for interviews back then?
A bit more than 10.
Wow, this year we’re inviting 120 students—very different.
Did your project start in September or a bit earlier?
My project started a bit earlier, but I officially started in September 2010.
What was your experience coming to IST like?
I knew it from before, because I visited for the interviews, and I went to the Open Campus Day, so I knew some people there already. I knew my likely supervisor and also some other professors from the interviews.
I still remember my first day: I didn’t really know what to expect from being in this new professional science environment. So I wasn’t sure how I should dress, for example. Then I met Krish on the first day, and I think he was running around in flip-flops as usual, so I thought, ok, maybe I shouldn’t have worried about that.[Laughs]
And did you have to do rotations?
All these things were there already, from the beginning, so I did rotations with Krishnendu Chatterjee, Tom Henzinger and Nick Barton. There were not many professors there yet. There were maybe 7 professors, and some of them had brought their own students, so there were 11 students. Very good faculty-to-student ratio.[Laughs]
Tell me what your PhD focused on, did you change directions a little bit over the course of your time there? And what led you to take that route?
When I joined I thought I would also work on Game Theory, inspired by this lecture given by Martin Nowak. Then I worked a little bit with Tom’s wife, Monika Henzinger, at the University of Vienna. She was working on algorithmic game theory and I was very fascinated by that topic. Krish had a collaboration, so I went a little bit into that direction.
But before I started at IST Austria, Krish proposed some projects to me and they were in the evolutionary game theory area, and I started working on that and I liked it and, then had some first results and it turned out that this was a collaboration with Martin—I didn’t know that! It made me kind of happy because that was how I got interested in IST Austria in the first place, and I could even work on this project. That was the coolest. We were in touch with Martin more often, and then he[Martin Nowak]suggested to me at some point, “I need someone in computer science to work on this particular project in cancer”. He then introduced me to another area that led me on this route.
And did you have to learn a lot about cancer and biology? How was that transition?
At the beginning of the PhD, not that much, because the problem is typically formalized by the supervisor already. So this is what Krish and Martin did for me. Then, the more senior you get, the more you identify problems, and you read more, and of course, you have to learn a lot of biology so that you can identify relevant problems to have an impact.
Looking back at your PhD at IST Austria, what were the most important things you took from it?
I very much liked—from the beginning—the interdisciplinary system at IST Austria. I also enjoyed the fact that in my first and second year I could take courses from different areas. That helped me a lot. Of the 7 people starting in that year, they were all in different areas. There were no two students in the same research group. And that was already in itself very cool, because when I was at TU Wien it was very different—I started with 700 students, not 7, and all of them were in computer science. Just a very different environment.
Were there any challenges? Being in a pioneer class starting at IST Austria, or being so interdisciplinary?
I think most of the time it was an advantage, because not many things were established, so you establish your own rules, and you just needed to convince some people that it was a good idea.
As for challenges? Of course if you want to be interdisciplinary then you have to go more outside of your comfort zone. It’s more time-consuming than just staying in your area and continuing what you have done for the last 5 years. But it’s also much more interesting.
And so you were there for 5 years, from 2010 to 2015? And then you’ve gone back to IST Austria to visit as well, and so you’ve seen it really grow and it’s changed a lot. What are some of the ways in which you think it’s changed most? Or what do you notice most when you last visited, how it’s different from the early days?
I mean in the early days I just knew every face and, if someone joined, then I’d be “Hmm, I’ve never seen that face”, and then we’d talk. Then we grew to 30 people, 50, 100, and you lose track of all the people. Now if I go back it’s more like, “huh, I’ve never seen most people before”. But that is how it is now. I think the culture is still very similar in many ways. On the bridge[common room area linking the Central Building and the Bertalanffy Building]people from different disciplines meet—they succeeded in keeping that kind of culture.
In your home town (and where is it?), what are the perceptions of IST?
It’s about 30km by car from IST Austria. In my hometown, almost everybody knows about IST, which is probably very different from the rest of Lower Austria where many people still don’t know about it. Also, many Austrian students here in Boston, you would think, should know about universities in Austria, but that’s not the case.[In my hometown,]I know many people and many people know me. They know I was at IST Austria for some time, so they got to know that there is some great science going on there.
You actually hear about the institute very frequently, on TV, or if you read the newspaper. People don’t realize however, that IST Austria is in Klosterneuburg, or in Gugging. But slowly they are realizing, this is that outstanding institution and there’s a lot of amazing science going on.
So during your PhD, what do you think is your project or paper that you were most proud of? Or most challenging maybe?
The most challenging project we only finished basically now[two years later], and I started it in my third year of PhD, so that took a long time.
And is that the one that was most recently published?
Yes, for that I had to learn a lot of new stuff, because typically I just do the theoretical analysis, mathematical modelling etc., and for this particular project we had to analyze a lot of data and in particular DNA sequencing data. So, I had to read up a lot on the literature and made a lot of mistakes along the way, starting with very naïve approaches in the beginning. But I gained more experience over the course of multiple years, and it has essentially become my main topic of research by now.
After your PhD you came here to Harvard. Why did you decide to take this step?
That was a rather easy decision for me, because I visited Martin frequently during my PhD so I already knew the environment here very well. And I knew it was kind of similar to IST Austria in that you have a lot of freedom to work on the problems that you’re interested in. I also knew many good people working in different areas, and of course it’s an advantage if you already started in that area and have interesting ongoing projects.
Could you just explain, what it is you work on and why it is important?
Essentially, I work on the evolution of cancer, and there are many different paths it can take—from the initiation of cancer, how it progresses, and then metastasis. So there’s a very long process which can take multiple decades from initiation to metastasis, and we basically want to understand which genetic events take place in that time to understand the evolutionary dynamics.
In particular, in the last couple of years I focused on the evolution of metastasis itself, so how it spreads from the primary tumor, which genetic precursors are needed for metastasis, where it travels to, and how long it takes.
In what ways would you say your computer science and game theory background contributes to that?
Now that sequencing of the genome has become so cheap, a lot of science groups generate a big amount of data. It is very hard for someone who has training in biology to analyze all this data in a sophisticated way—a computer scientist or people who have training in that area can be very useful for that. What we do here in addition to analyzing these data is we try to find patterns and then make mathematical models to try to understand the underlying mechanisms—what would lead to metastasis, for example.
A lot of projects that you work on are collaborate projects—who are the type of scientists you work with the most? Or are these doctors?
We work with many physician scientists who got their degree as a medical doctor and then transitioned into science and did another PhD. We collaborate with many people at Johns Hopkins for example. We also work with leading cancer physicians at an oncology lab in New York. They have access to cancer patients and can perform autopsies to obtain cancerous tissue samples found around the body and sequence all these different tissue samples. You can learn a lot about the genetic mutations present in these different metastases, and reconstruct the evolutionary history and build a picture of how the metastases might have evolved over multiple decades.
Do you find it challenging to work with people who have very different backgrounds to you? Do you feel you have to adapt your talks your presentations to audiences?
Certainly. Sometimes when you discuss a specific problem, probably our collaborator might think “oh this guy doesn’t understand even basic biology”, and then when we explain our mathematical models we think “they haven’t understood anything of what we did in the last year”. It takes a long time, but over the course of collaborations you get to learn more and more about the methods that other people use, and I find that extremely interesting.
We were saying about how Martin Nowak has been working in many different fields: what do you think makes that possible?
I think the basics of doing mathematical models, understanding evolutionary dynamics, and the basic principles are similar across many field. If you are interested in the evolution of organisms and evolution of different diseases, how you would study them in a theoretical fashion is in fact very similar. One of the papers we produced during my PhD was combination therapy for cancer—how you combine different drugs. Then Martin said, that’s exactly what we did 10 or 15 years ago, in viruses, in particular, for HIV. They couldn’t treat it for a long time successfully, and then they started combining different drugs and that also came out of these mathematical models and it suddenly worked out. For cancer we could basically use these insights that he got from viruses and translated those to cancer.
Where do you hope to go from here?
That’s a very difficult question. Of course I very much enjoy what I’m doing, so I would like to stay in academia. I also benefited very much from the environment to which I was exposed at IST Austria with so many excellent people and now also at Harvard—there is this whole network of researchers. Essentially, you get to know many good people and they again know many good people, so I hope to end up at some institute where I can continue to benefit from an excellent interdisciplinary environment and I hope it will bring me to the next big thing.
But as you know the job market in academia is extremely tough, so it’s very hard to predict where you will actually land. If my job will be in Europe or central Europe, that would be amazing; if it’s somewhere else, we’ll see.
If you had to give advice to students at IST now, what would you say to them?
Work on the problems that you are most passionate about. I think it’s very important to not just solve a problem given to you—of course it helps to read up on a particular area to understand what the science is about—but very early on start working on your own ideas. And learn from your mistakes—and often, setbacks. Don’t be afraid to ask other people for advice. I think from these you learn the most.
- extended runs or biking trips
- classical music
- in Stanford tasting the amazing wines in California
- in Austria voluntary fire brigade
Thorsten Tarrach was a PhD student in the Chatterjee group at IST Austria, and is currently working as a research engineer at AIT in Vienna
May Chan from Graduate School Office interviewed Thorsten at his workplace at AIT to find out what it was like to leave IST Austria.
What is your position at AIT and what do you do here?
I’m a research engineer at AIT (AIT – Austrian Institute of Technology). There are two career paths for scientific/technical staff, which are research engineer, and scientist. For me the research engineer is a perfect position because it combines both the technical aspect of doing the implementation, which I’ve always enjoyed, but it also has a scientific side to it, where I’m involved in the paper writing and will be co-author on some of the papers. I will also be doing theoretical work before we can start implementing things. It’s not like your typical implementation job in industry, where you use existing technologies—here at AIT we’re really working at the forefront of technologies.
Can you give an example of what kind of research project or implementation project you’re working on?
My first task has been to work on MoMuT [Model-based Mutation Testing], an existing framework that has been developed mostly at AIT. In the computer industry, a large part of the work is to test programs, which is a very time-intensive and labor-intensive task. We want to automate that—we want to automatically generate those tests for the customers.
Presumably, mutation is not in the biological sense?
Essentially, we are mutating the specifications and the mutated one is wrong. Then we’re trying to find a test case that can distinguish the wrong one from the right one. So a test case is essentially a set of inputs that we use to observe the output the computer gives us. If you had for instance an input “3” and the output given by the computer is the same as the correct one, then you couldn’t see any difference and couldn’t see if the system was behaving incorrectly. But if you gave it the value “0” and the output is not the one we expected, then the value “0” would be a good test case. So, we are trying to find those inputs for which the system shows deviation from the correct execution.
It’s an exciting, new thing that’s being done here, something that you can writes papers on. We’re not just using existing techniques, but developing new techniques here, yet at the same time–which is different from at IST Austria—here we’re really trying to create a product out of that research that’s usable for industry. At IST Austria, we would always stop with a research prototype and a few examples—you would never bring it to the production level.
Can you tell us about your thesis work at IST Austria and who you did your research with?
I worked with Tom Henzinger at IST Austria. He’s the President and also one of the most senior computer science researchers in Europe. It was a great privilege to be able to work with him. Despite all his obligations he actually has quite a lot of time for his students. We had very regular meetings and there were four students in the group, which is really an excellent ratio.
What was your daily life like as a PhD student?
I think it really depends a lot on what’s coming up in the next couple of weeks. I think my experience work-wise is that it was quite cyclic, coming in recurrent waves. The work intensity really goes up before the deadlines, and after that it’s much more relaxing. Generally what I also felt as a student and as a postdoc, people are really engaged in their work all day round, seven days a week. Whereas here[at AIT]the working days are much more clear-cut. After eight hours you go home and then you can forget about the work.
At IST Austria I was working in a very similar field, so we worked on verification—we were trying to prove that the software is correct. This is a bit different from the testing approach that’s being done here[at AIT]. But it’s also much more restrictive in terms of what size of programs can be handled because the technique we used was computationally more expensive.
We went a little bit further, we didn’t just want to see if the program is correct or not, but we wanted to automatically repair the program. This is called synthesis. Synthesis or automated program repair are somewhat synonymous. This is what I worked on for my thesis. So we would take a computer program—essentially software and source code—and then I developed for my thesis a little tool or a research prototype (it’s not fully usable) and that tool would analyze the program, find certain kinds of defects, and automatically repair the code of the program. It deals with a certain class of programs called concurrent programs.
So when did you first become interested in computer science?
I was already interested as a child. It started with my father’s Comodore 64, where I would try some simple basic programs. I was probably eight back then. A bit later we got the first actual PC, and my dad brought home a box with Visual Studio 2. Then I started writing small programs, and I remember when I was fifteen, I took part in a local competition where people present different programming work that they did. I wrote a vocabulary trainer. Essentially it had a database where it had German and corresponding foreign language words. It would show you the German one and ask you what it should be in the foreign language—you could type this in, and it would tell you if it’s correct or not.
I wanted to study computer science very early on. I started my bachelor’s at the University of Saarland, Saarbruecken. And during my bachelor’s I went on Erasmus (a European exchange program) to Trinity College in Dublin, Ireland, staying there for 9 months. I also did a 9-month internship at Microsoft in Dublin, doing software development.
I then did my master’s in 2010 and worked for 2 years in a small start-up like environment. After 2 years I was interested in doing a PhD. For personal reasons, I chose Vienna and my former colleagues happened to tell me about the work of Krish Chatterjee. I wrote Krish an email, and a few days later I got an email from the Graduate School Office, saying they would like to see a full application. I was very lucky that I was invited for an interview (there were about 600 applications).
How did you end up in Tom Henzinger’s group?
I heard about Krish but once I applied and read through the list of professors, I found Tom’s research interests were much closer than mine. In the end I did rotations with Krzysztof Pietrzak, Christoph Lampert and Tom Henzinger, and it was clear that working with Tom was what I wanted.
At the beginning I was working with Pavol Cerny, formerly postdoc in Tom’s group (now a professor at UC Colorado Boulder), as well as with Arjun Radhakrishna, another PhD student. It was very lucky for me I could work with them. They had a very good idea, and my task was to do the implementation, which is what you typically start with as a PhD student. I worked on that during my rotation, and worked very hard on it—during weekends as well. The paper got accepted at CAV[Computer-Aided Verification], and I got my first CAV paper before I even affiliated. And I could never have done it by myself due to the lack of experience, but this worked out really nicely, and that’s also what enabled me to finish my PhD after 4 years. I essentially continued working with both of them throughout the entire PhD and we produced a succession of 4 papers. We were all lucky that these papers got accepted at first attempt.
What did a regular day as a PhD student look like for you?
I typically went to work rather early, coming in at 8:30 or 9:30 latest. For me the morning was usually the quiet time when you get a lot of work done, I find. I particularly enjoyed the lunch break with others, and we usually went for a coffee right after. I enjoyed this social interaction. In the afternoon, we usually had meetings scheduled and there were talks.
When you were at IST Austria, did you live in Vienna?
I was mostly Vienna-based. I didn’t make use of the socializing opportunities at IST Austria as much as one could have.
Did you enjoy the campus?
Yes, the environment is very nice. The atmosphere there is also such that you’re encouraged to take breaks, there’s a gym, people go running and so on.
Did you interact a lot with students from other subject areas?
In the first year, we interacted a lot as we shared an office so we were bonding a lot. But when you join different research groups, you get separated a bit more. In the end you hang out mostly with people from your own and related groups. You don’t see students from other subject areas as regularly anymore. But you still bump into them on campus, in the gym, and find out what they are working on.
Think & Drink was also a good way of bringing together people.
On the topic of work/life balance, did you engage in any extracurricular activities?
I was socializing regularly, mostly with other students at IST Austria.
Any happy memories at IST Austria?
Some of the best times at IST Austria were the retreats. PhD students organize their own retreats, and the institute has its own retreat. But the student one is really the best. You get to know other students very well through those.
What do you think of your transition between being a PhD student and now? How does one prepare during the PhD for life afterwards?
I think AIT is a bit special, in that it is not as strict as an industry job, but I think there are a few common points that you experience in transition to both AIT or industry, which is that you have a much more clear-cut work/life balance, both in terms of time and the tasks that you have to perform, which are usually very clearly laid out. As a PhD student, the first thing is you have to motivate yourself, you have to keep track of your own time, in the sense of making sure you do enough work, or—for some people this is more of a problem—know when you need a break.
Did IST Austria in anyway prepare you for your current job?
I chose this job at AIT because I thought my knowledge from IST Austria was useful. I was lucky in that IST Austria didn’t just prepare me in the abstract sense, such as knowing how to work on your own on your projects—these are things that doing a PhD and being at IST Austria can equip you with; but also with the concrete knowledge from the papers I read from my projects, from the write-up—these are very applicable to my current position.
Tom suggested to me that a PhD is always useful, no matter what job you end up doing—you learn how to acquire new knowledge yourself, by learning how to learn. This skill is transferable to other realms, whether you take up a research or industry position, or join a start-up.
I’m happy at AIT. One benefit of this job is that it’s permanent. One of the reasons why I didn’t pursue an academic career was that you constantly have to move. And it’s unclear, even if you’re very good, if you will get a position. I felt like settling down and having a job where, if I wanted to, I could stay.
What advice would you offer to current PhD students, or those who are thinking of doing a PhD?
First, you have to be prepared to work hard for it. But of course at the same time you need to take care of your work/life balance. You can’t be working hard for four years non-stop. A good start of your PhD—a lot is in the hands of your advisor, but it’s also good to have more senior PhDs or postdocs, to work with you on the project, and to see themselves as having a supporting role for your first paper. It’s good to listen to advice of both your supervisor and the people you’re working on the paper with. They have more experience and can provide guidance on how to, for instance, work on collaborations with other groups. Be humble, work hard, and understand that the hard work will pay off whether it is now or later.
It’s important to not only focus on the work you’re doing at the moment, but to also keep a broader view of your research area, to listen to talks, go to conferences, irrespective of whether it’s directly related to your current project or not.
And while IST Austria basically offers an environment where you don’t have to speak any German, many people consider going to industry after their PhD and staying in Vienna, so learning some German could prove useful. A few PhD students I know have stayed in Vienna and settled with industry positions.
Martin Chmelik was a PhD student at IST Austria. He now works for TTTech. TTTech (https://www.tttech.com/) is the leading supplier of dependable networking solutions based on time-triggered technology and modular safety platforms. At IST Austria Martin Chmelik was in Krish Chatterjee’s group. His thesis with the title “Algorithms for Partially Observable Markov Decision Processes” won the Best Thesis Award at IST Austria 2016.
In an interview with Daniela Klammer and Kathrin Pauser he answered some interesting questions about his work.
What’s written on your business card?
Martin Chmelik, research engineer at TTTech
What’s the essence of your job?
I am working in a research group at TTTech and in our team we are building the very first versions of products. We are doing research in the area of scheduling, real time control and computation in hypervisors and building those into very early version of products that we then show to our potential customers.
Where do you see yourself in the future?
The thing with computer scientists nowadays is that the challenges and opportunities are everywhere. So one doesn’t need to worry too much about the long term future and more on the current state and be happy with the work you are actually doing.
What is your academic background?
I did my masters at Masaryk University in Brno. I went to an Erasmus in Denmark in university of Aalborg and then I joined IST.
What role did IST play for your career?
A very important one. There is some truth in the saying that you become the average of the five people you work most with. So in that sense you should surround yourself with very smart and hard working people. I think that IST was exactly the right place for me in that sense. So I think it played a very important role in my life.
Give 3 pieces of advice to current IST Members
The first one would be to enjoy your time at IST Austria and use everything that IST is offering. I think it is excellent environment and current students should make use of it.
Second, is to travel to conferences, to join workshops, organize events. Talk to people share ideas get new insights, be known in the community.
The third one is more general to ask questions. Because it seems to me at the moment when you don’t ask a question because you are afraid it is not a smart enough question then it actually accumulates. So from every first moment you should ask questions that are interesting for you.
What is your favorite memory of IST Austria?
This should probably be something like defending my PhD thesis or something like that. But actually form me it could be the table soccer tournament that took place annually. I was playing regularly but I never won. This kind of stays in my memory.
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