Kauste and partner Tomi Rantamäki represented Finland at both the 2016 and 2017 World Mixed Doubles Curling Championship. In 2016, the pair won their group with a 6–0 record, and made it to the quarterfinals where they lost to Russia. They would eventually finish in 7th place. In 2017, they finished 5–2 in pool play, and again lost in the quarter finals, this time to the Czechs. They would again finish 7th. Their pair of seventh-place finishes would qualify the team to represent Finland in the 2018 Winter Olympics. There, they won just one game, and finished in last place.