After graduation worked with ITEPh: until 2013 - as Head of the Laboratory of Physics of Elementary Particles.

[3] In 1997 he defended his doctoral thesis "Experimental study of hadron interactions of a photon using the H1 detector at the HERA accelerator".

In February 2013, Rostovtsev, together with journalist Sergey Parkhomenko, biologist Mikhail Gelfand, and physicist Andrey Zayakin, founded the volunteer community network Dissernet, which exposes fake dissertations.

Rostovtsev developed key software for dissertation and publication verification system.

He was the initiator and leader of the work for discovering translation plagiarism in the papers of Russian authors in foreign predatory journals that formed the basis of the corresponding Report of the Commission in 2020.