[2] He began his senior club career playing for Honka and made his league debut at age 19 in 2008.

Aalto was born in Espoo, Finland, raised in Honka's youth ranks, he made his first team debut on 27 April 2008, at the age of 19, in a match against MYPA.

[4] Aalto made his league debut for the club on 19 April 2015, playing all ninety minutes of a 1–0 home victory over RoPS.

In the winter of 2017 Aalto signed a contract with VfB Oldenburg, in the German Regionalliga.

[6] Aalto made his competitive debut for the club on 5 February 2017 in a 3–3 draw in the league with Lupo Martini.