I am working on efficient algorithms for scalable data analysis including:
This semester I am organizing the Theory Seminar. Recently created/taught/organized:
M. Kearns,
A. Roth,
S. Wu,
G. Yaroslavtsev
Private Algorithms for the Protected in Social Network Search PNAS 2016 (Proceedings of the National Academy of Sciences), via direct submission. 
Spotlight story on the Penn front page: Balancing Privacy and Security in Network Analysis.
External media coverage: ACM Tech News / The Daily Pennsylvanian, Schneier on Security, AAU, Quartz, Pacific Standard, Wired (German), The Naked Scientists Podcast and Vice Motherboard.
S. Chawla,
K. Makarychev,
T. Schramm,
G. Yaroslavtsev
Near Optimal LP Rounding Algorithm for Correlation Clustering on Complete and Complete kpartite Graphs STOC 2015 (47th ACM Symposium on the Theory of Computing). 
See the Wikipedia article on correlation clustering for more details.
For applications in data mining see a Yahoo! KDD'14 tutorial by Francesco Bonchi, David GarciaSoriano and Edo Liberty.
P. Berman,
S. Raskhodnikova,
G. Yaroslavtsev
L_{p}Testing STOC 2014 (46th ACM Symposium on the Theory of Computing). 
Simple introduction by Sofya Raskhodnikova in the Encyclopedia of Algorithms (Springer).
Open problems from JHU workshop on Sublinear Algorithms [pptx, pdf].
Oded Goldreich's review on “My Choices”. Property Testing Review Post 1, Post 2.
A. Andoni,
A. Nikolov,
K. Onak,
G. Yaroslavtsev
Parallel Algorithms for Geometric Graph Problems STOC 2014 (46th ACM Symposium on the Theory of Computing). 
Notes by Thomas Steinke from Jelani Nelson's Algorithms for Big Data Course at Harvard
Notes by Kui Tang from Alex Andoni's Algorithmic Techniques for Massive Data Course at Columbia.
V. Karwa,
S. Raskhodnikova,
A. Smith,
G. Yaroslavtsev
Private Analysis of Graph Structure VLDB 2011, Research track (37th International Conference on Very Large Data Bases). 
Full version in ACM Transactions on Database Systems.
P. Berman,
A. Bhattacharyya,
K. Makarychev,
S. Raskhodnikova,
G. Yaroslavtsev
Approximation Algorithms for Spanner Problems and Directed Steiner Forest ICALP 2011, Track A (38th International Colloquium on Automata, Languages and Programming), special issue of “Information and Computation”. 
Runnerup for the Best Paper Award.
Open Problem #2 from the Princeton Workshop on Approximation Algorithms. See also my slides.
A. Kojevnikov,
A. Kulikov,
G. Yaroslavtsev
Finding Efficient Circuits Using SATsolvers SAT 2009 (12th International Conference on Theory and Applications of Satisfiability Testing).

Amplification of OneWay Information Complexity via Codes and Noise Sensitivity
ICALP 2015, Track A (42nd International Colloquium on Automata, Languages and Programming).
Certifying Equality with Limited Interaction
RANDOM 2014 (18th International Workshop on Randomization and Computation).
Beyond Set Disjointness: The Communication Complexity of Finding the Intersection
PODC 2014 (33rd Annual ACM SIGACTSIGOPS Symposium on Principles of Distributed Computing).
Lower Bounds for Testing Properties of Functions over Hypergrid Domains
CCC 2014 (29th IEEE Conference on Computational Complexity).
Beating the Direct Sum Theorem in Communication Complexity with Applications to Sketching
SODA 2013 (24th Annual ACMSIAM Symposium on Discrete Algorithms).
Learning PseudoBoolean kDNF and Submodular Functions
SODA 2013 (24th Annual ACMSIAM Symposium on Discrete Algorithms).
Accurate and Efficient Private Release of Datacubes and Contingency Tables
ICDE 2013 (29th IEEE International Conference on Data Engineering).
^{*} This is the only paper with nonalphabetical ordering of authors.
PrimalDual Algorithms for NodeWeighted Network Design in Planar Graphs
APPROX 2012 (15th International Workshop on Approximation Algorithms for Combinatorial Optimization Problems).
Steiner TransitiveClosure Spanners of dDimensional Posets
ICALP 2011, Track A (38th International Colloquium on Automata, Languages and Programming).
Online Algorithms for Machine Minimization [Preprint on arXiv].
I participated in ACM ICPC and TopCoder competitions (as griffon) competing and setting problems in TopCoder Open Algorithms Finals.
I was teaching advanced classes in algorithms for highschool students for ~5 years, coaching teams for algorithmic competitions. I participated in preparation of training camps and contests for Russian Olympiad in Informatics and International Olympiad in Informatics (both in Russia and in the U.S.).
In 2009 I cofounded a nonprofit organization focused on advanced extracurricular education in algorithms for highschool students (5 – 10 grades) in St. Petersburg, Russia. In 2013 it was expanded to Moscow and Yekaterinburg.
In the early days we were supported by , and . Now donations are welcome!
If I am not working then I am probably practicing for the next (more pictures). Let's do it together! ;)
In 2015 I am participating in USAT Age Group National Championships in Olympic Distance and Ironman Lake Tahoe.
In 2007–2008 I was lucky to be a part of the FBReader team. This is an open source free eBook Reader project.
We developed the first version of FBReader for Android (now >5M downloads worldwide on Google play).
There are some things I can't prove but rather just believe in. E.g. this logo I designed and proposed for the CSTheory website.
St. Petersburg Academic University is a unique center for continuous education in physics and engineering, run by Zhores Alferov, a Nobel Prize winner in Physics. In 8 years there I finished high school, B.S. and M.S. (a pilot class in theoretical computer science where I was the first student). I am forever grateful to all my teachers during those happy years!
Here is a recent video (in Russian) about the new bachelors programs at the Academic University.