Walden is originally from New Plymouth and was schooled at Francis Douglas Memorial College in his hometown where he played first XV rugby.
[4][6] His first taste of senior rugby came with the Otago Razorbacks in 2013, making 5 appearances including 1 start as the men from Dunedin finished as runner up on the Championship log before being defeated by Hawke's Bay in the semi-finals.
2015 was much more positive for both Walden and the Razorbacks with him starting 9 times and scoring 1 try and Otago finishing 3rd on the log before being comprehensively defeated by Wellington in the semi-finals.
Overall he scored one try in 6 matches while still a wider training group member in 2016 and new Highlanders head coach, Tony Brown saw fit to promote him to the full squad for 2017.
[4][5] Walden was a member of the New Zealand Under-20 side which finished 4th in the 2013 IRB Junior World Championship in France, although he didn't get any game time during the tournament.