Tuomisto lived in Turku in the 1990s and played as a goalkeeper at an amateur level with local clubs in lower divisions.
Later, he moved to Lohja to study youth leading in Kanneljärven Opisto folk high school.
Since 2007, Tuomisto had traveled to Italy every year at his own expense to get familiar with different clubs and organisations at various levels, including Piacenza.
[3] In 2014, Tuomisto was named a goalkeeping coach for Arzaghena in Italian Serie D and worked for the club for five months.
[8] Since the early 2021, Tuomisto has been working in the coaching team of manager Francesco Farioli, starting in Turkish Süper Lig clubs Fatih Karagümrük and Alanyaspor, before being named the goalkeeping coach of French Ligue 1 side Nice in July 2023.