Complex sentence: JetBrains was founded in 2000 as a private company, by Sergey Dmitriev, Eugene Belyaev and Valentin Kipiatkov.
Split into simpler sentences: JetBrains was founded in 2000 as a private company. JetBrains' cofounders are Sergey Dmitriev, Eugene Belyaev and Valentin Kipiatkov.