Владимир Воеводский (who publishes in English as Vladimir Voevodsky) (web site) is a Russian mathematician working in the Institute of Advanced Studies.
He received a Fields medal in 2002 for a proof of the Milnor conjecture. The proof crucially uses A1-homotopy theory and motivic cohomology developed by Voevodsky for this purpose. In further development of this in 2009 Voevodsky announced a proof of the Bloch-Kato conjecture.
After this work in algebraic geometry, cohomology, homotopy theory Voevodsky turned to the foundations of mathematics and is now working on homotopy type theory which he is advertizing as a new ””univalent foundations” for modern mathematics.
See also the English Wikipedia article .
An interview is here.