Kairys had been a part of
Lietuvos rytas Vilnius youth system from 2006 to 2011, when
Perlas Vilnius was dissolved. He then joined
Pieno žvaigždės Pasvalys for four straight seasons. During his fourth season in
Pasvalys, Kairys averaged 10.9 points, 5.9 rebounds in the
Lithuanian Basketball League. On July 28, 2015 he signed with
Muratbey Uşak Sportif of the premier
Turkish Basketball League. Kairys spent the 2018–19 and 2019–20 seasons with
Rytas Vilnius of the
Lithuanian Basketball League. He averaged 7.5 points and 3.9 rebounds per game in 2019–20. On August 6, 2020, Kairys signed with
Afyon Belediye of the Turkish
Basketbol Süper Ligi. On 25 February 2022, Kairys signed with Rytas Vilnius. On 30 June 2023, Kairys signed with
Covirán Granada of the
Liga ACB. On January 23, 2024, he signed with
Mersin MSK of the
Türkiye Basketbol Ligi (BSL). On June 26, 2024, he extended his contract with the club, after the promotion to
Basketbol Süper Ligi. == International career ==