During the war in Donbas from 2014 to 2022, Kovalchuk took part in successful operations to liberate settlements in Donetsk Oblast before assaulting the Luhansk International Airport.

In 2018 Kovalchuk studied for a Master of Public Administration degree at the Ivan Chernyakhovsky National Defense University of Ukraine.

He was recognised as the best graduating officer and received the Queen Elizabeth II of Great Britain sword in recognition.

Kovalchuk decided against a career in engineering and in 1994 transferred to the Guards Higher Tank Command School at Kharkiv, from which he graduated with honours in 1997.

In 2004 he attended the Ukrainian Academy of Defence, majoring in "combat application and management of the actions of units of the Ground Forces".

Kovalchuk served on a United Nations Interim Administration Mission in Kosovo peacekeeping operation from 2005 to 2006, as deputy commander of the Ukrainian contingent.

Kovalchuk then led part of the brigade on a march to Shchastya in Luhansk Oblast to go the relief of other Ukrainian troops.

[4][2] In March 2016 Kovalchuk was appointed chief of staff and deputy commander of the Highly Mobile Landing Forces (airborne units).

Changes made included the replacement of the blue beret for airborne troops, associated with the Soviet and Russian armies, with a red one.

[9] Kovalchuk's wife Olena is an airborne officer; they met when she chastised him, her senior, for wearing an unpolished belt buckle.