Liendo was named to his first national team at the 2018 Summer Youth Olympics held in Buenos Aires, Argentina. Liendo's first senior team was at the 2019 World Aquatics Championships, where he competed in the 4x100 men's medley. The team finished in 10th place and did not qualify for the finals. Later in the year, Liendo won 3 medals at the 2019 FINA World Junior Swimming Championships in Budapest, and for that performance was named as Swimming Canada's junior male swimmer of the year. At a time when Swimming Canada was enjoying enormous success with it's women's program while the men's program was struggling, Liendo was widely identified as perhaps the most promising emerging talent on the men's side.