Mick Campion took over as head coach and prepared Johan for the 2012 Australian Titles and 2012 Oceania Championships, which he won and booked at spot on the 2012 London Olympic Team.

Linde went on to win the 2012 Australian and regional 2012 Oceania titles to qualify for the 2012 London Olympic Games, beating the highly rated Tongan Junior Fa in the final, who in turn had beaten Joseph Parker in the semi-final.

In the lead up to the London Olympic Games, Linde fought Joseph Parker in the 2012 Belgrade Winner final, narrowly losing on a countback.

After the Perrottet Liberal Government was defeated at the 2023 New South Wales state election, Johan turned professional with his first fight against Parminder Singh (TKO Rd 2) in June 2023.

He fought for the Australian National Boxing Federation Australasian Heavyweight Title against Stevan Ivic (Split draw) in Southport, Queensland.