[1] As a junior, he spared for Pierre Charette at the 2002 M&M Meat Shops National, which was played in his home town of Sault Ste.
For the 2011–12 season, the team entered two Slams, the 2011 World Cup of Curling where they had a 2–3 record) and the 2011 BDO Canadian Open where they made the playoffs for the first time, but lost in the quarter final.
The team won The Dominion 2013 Northern Ontario Men's Curling Championship once again, qualifying for the Brier for the fourth straight year.
At the Olympics in Sochi, they led Canada to a 9–3 victory in the men's final, defeating Great Britain to claim the gold medal.
After posting a 10–1 round robin record in first place, they won the 1 vs. 2 game sending them to the finals against the defending Brier champions, Team Canada (skipped by Pat Simmons), which they lost.
The 2016–17 season would be the best to date for the Jacobs rink on the World Curling Tour, winning two slams, the 2016 Boost National and the 2017 Humpty's Champions Cup.
The team again represented Northern Ontario at the 2018 Tim Hortons Brier, making it to the playoffs with an 8–3 record, but lost to Alberta's Brendan Bottcher rink in the 3 vs. 4 game.
The team had Marc Kennedy playing third, filling in for Ryan Fry, who was on sabbatical following unsportsmanlike behaviour and excessive drinking at the 2018 Red Deer Curling Classic.
Jacobs lost the 1 vs. 2 game to Kevin Koe and the semifinal to Brendan Bottcher resulting in the team getting the bronze medal.
Team Jacobs won three straight Grand Slam events, at the Tour Challenge, National and the Canadian Open.
[5] Team Jacobs played in two tour events during the 2020–21 season, winning the Stu Sells Oakville Tankard and losing in the qualification game of the Ashley HomeStore Curling Classic.
[7] Team Jacobs began the 2021–22 curling season by winning the 2021 Oakville Labour Day Classic, then lost in the final of the 2021 Masters.
In May 2022, after Brad Jacobs decided to step away from curling for at least a season, Harnden joined Brad Gushue's Newfoundland and Labrador rink, replacing their long-time second Brett Gallant, who had decided to move to Alberta with plans to marry mixed doubles partner Jocelyn Peterman and join Brendan Bottcher's team in the western province.
Harnden had already served as the Gushue rink's alternate at the 2022 world men's curling championship the previous month and earned a silver medal.