Moulds started out his career with the Northland Taniwha during the 2013 ITM Cup and quickly established himself as a regular member of their starting fifteen. 2014 was a good year for both the Taniwha, who finished 3rd in the Championship standings with 5 wins and 5 losses and for Moulds, who played 10 times and scored 2 tries.
2015 and 2016 saw Moulds captain the Taniwha in what turned out to be 2 disappointing seasons. As captain, however, he was a guaranteed starter and made 16 appearances across the 2 seasons, scoring 1 try.[2]
Impressive performances at provincial level were rewarded in 2015, when he was named in the Blues wider training group for the 2015 Super Rugby season.[7] He made 1 appearance in his debut season, as a replacement in a match against the Stormers, but further good provincial performances saw him named in the Blues full squad for 2016. The presence of experienced hookers in the shape of All BlackJames Parsons and the well traveled Quentin MacDonald meant game time was rare for Moulds who had to take the role of third choice for the Blues. He did get on the field twice during the season, with both appearances coming from the bench.[2]
Moulds was again named in the Blues squad for 2017 where he would compete with Parsons and Waikato newcomer Hame Faiva for the number 2 shirt.[4]
Moulds was a member of the New Zealand sevens wider training squad in early 2014 and was part of the side which competed in the Wellington Sevens in February 2014.[11]