In 2006, he graduated from secondary school in the town of Makiivka and started courses at the Institute of Informatics and Artificial Intelligence of Donetsk National Technical University.

According to a biography published in Yunost magazine, after attending the university, Aseyev travelled to Paris, where he applied for service in the French Foreign Legion, then came back to Ukraine and tried many professions such as loader, intern at a bank, grave digger, operator in a mailing company, and shop assistant.

[citation needed] Aseyev's mother (living in Makiivka near Donetsk) visited his apartment and saw traces of illegal entry and search.

[9] His fellow student and former MP Yehor Firsov reported Aseyev's disappearance on 6 June accusing Russia-backed militants of kidnapping.

[4] On 16 July 2017, an agent of the DNR's Ministry of State Security confirmed to Aseyev's mother that her son was in their custody and that he was suspected of espionage.

[13] Amnesty International, Committee to Protect Journalists, the European Federation of Journalists, Human Rights Watch, the Norwegian Helsinki Committee, the Organization for Security and Co-operation in Europe, PEN International, Reporters Without Borders and the United States Mission to the Organization for Security and Cooperation in Europe called for his immediate release.

[20] Stas Aseyev and his less-known colleague Oleh Halaziuk were released (as part of a controversial prison exchange between the DPR, the Luhansk People's Republic and Ukraine) and handed over to Ukrainian authorities on 29 December 2019.

[7] After his release, Aseyev took an active social and political position, dealing with the rights of captives of illegal prisons in Russia and on occupied territories.

On 29 January 2020, Aseyev delivered a speech at the Council of Europe in which he asked the member states to put pressure on Russia to release the captives.

[22] On 14 February 2020, Aseyev met with a group of US senators at Radio Liberty's Prague office to discuss the release of the remaining captives in the occupied territories of Donetsk region.

The reason for demobilization was the disbandment of his battalion due to losses and the refusal of the command to transfer Aseyev to the Main Directorate of Intelligence.

[30] While remaining in his native Donbas region from the beginning of Russia-sponsored hostilities there, Aseyev contributed short dispatches on the situation on the ground to prominent Ukrainian and international media, writing under the pen name of Vasin.