From 2006 to 2007, he was the commander of the 27th separate guards motorized rifle Sevastopol Red Banner brigade named after the 60th anniversary of the USSR, and from November 2007 to May 2009, he was a commander of the 2nd guards motorized rifle Taman Order of the October Revolution, Red Banner, Suvorov Order of the M.I.

[citation needed] In June 2013, Chayko was the Deputy Army Commander of the Central Military District.

From April 2017 to November 2018, Chayko was the Chief of Staff - the First Deputy Commander of the Eastern Military District.

[8] From November 2018 to February 2019, he was the Deputy Chief of the Military Academy of the General Staff of the Armed Forces of Russia.

[15] Human Rights Watch states that he may be responsible for widespread attacks against hospitals, schools and populated areas in the Idlib Governorate.

[15] It is alleged that during the 2022 Russian invasion of Ukraine, troops under Chayko's command tortured and executed hundreds of Ukrainian civilians during the Kyiv offensive.

[15] War crimes prosecutors in Ukraine are researching whether Chayko directly ordered specific atrocities.