Väätäinen started at the Junior World Championships in 1991 in Reit im Winkl for the first time in an international competition and was able to win the silver medal in the team competition with the team. A year later, in February 1992, he started in Lahti for the first time in the World Cup , but was only 44. At the Junior World Championship in Vuokatti , which took place shortly afterwards , he was able to win the gold medal again with the team. In the 1992/93 season he competed in several World Cup competitions and was able to achieve his first World Cup points. Since he was able to place himself in the top 30 consistently in the 1993/94 season, he took part in the 1994 Winter Olympics in Lillehammer . There he took 30th place on the normal hill and was fifth with the team. After the Olympic Games, he entered the World Ski Flying Championships in Planica in 1994 and finished in 14th place. A week later he was able to jump into the top ten for the first time in eighth place at the World Cup competition in Thunder Bay . In the 1994/95 season Väätäinen only took part in four World Cup competitions, in which he fought for a place in the second round. Also in the following season 1995/96 he often missed the points, but was able to celebrate his only podium in the World Cup on February 28, 1996 when jumping from his home hill in Kuopio with third place. In the years that followed, he only competed sporadically in the World Cup and was rarely able to reach the final. After the 2000/01 season, he finally ended his active career.
Coaching
In 2002 Väätäinen started working as a coach for the Finnish B team. In 2004 he finally became assistant coach of the senior national team. After Tommi Nikunen's engagement ended , he was introduced as the new head coach of the Finnish national team in April 2008. He initially received a two-year contract. After this had expired, Väätäinen moved to Japan in 2010, where he looked after the Tsuchiya Home Ski Team in Sapporo , for which Noriaki Kasai and Ryōyū Kobayashi , among others, start. Väätäinen has been coaching the Finnish national team again since 2020.