Prof. Dr. Tobias Friedrich

Janosch Ruff

Chair for Algorithm Engineering
Hasso Plattner Institute

Office K-2.19/20

E-Mail: Janosch.Ruff(at)hpi.de

Research Interest

I am interested in theoretical computer science and algortihms. My current focus lies on the structures that are emerging in scale-free networks.
Thus, the center of my research revolves around the revelation of patterns occuring in random graphs and exploit their properties for an efficient algorithm design.
On the flip side, I am guided by models such as Hyperbolic Random Graphs for the average-case analysis of algorithms on realistic input instances.

I conduct myself under the guideline "Everything should be made as simple as possible, but not simpler".

Particulary I enjoy conjuring results via probability theory and using the power of randomness:

  • Randomized Algorithms
  • Probabilistic Method
  • Incompressibility Method
  • Information Theory


[ 2023 ]

2023 [ nach oben ]

  • On the Giant Component of... - Download
    Bläsius, Thomas; Friedrich, Tobias; Katzmann, Maximilian; Ruff, Janosch; Zeif, Ziena On the Giant Component of Geometric Inhomogeneous Random GraphsEuropean Symposium on Algorithms (ESA) 2023: 20:1–20:13


Since 2021Ph.D. student at the chair for Algorithm Engineering, HPI Potsdam 
2017 - 2021Master of Science in Computer Science (minor studies in Neuroscience)
University of Göttingen, Göttingen
Thesis: “Kolmogorov Complexity, Recursive Enumerations and Universal Probability”
2012 - 2017Bachelor of Science in Business Information Systems
University of Göttingen, Göttingen
Thesis: “Development of a Gateway for Protocol Translation in IoT with ICN”
Spring 2015Exchange Semester at UPAEP, Puebla, Mexico




As a Lecturer

As a Teaching Assistant

As a Tutor

Other Activities

During my studies I made extensive use of academic freedom and offers made by my university to study one semester abroad in Mexico and to travel for half a year in South America. During my Masters I did two internships in Iran and Brasil each two months. 

Besides Computer Science and Mathematics, I am very much interested in foreign languages. Next to English & German I speak fluently Spanish & Portuguese. I also have basic knowledge in French & Italian what I am interested to improve within the near future.

I very much enjoy classical music and to play the piano particularly Chopin.