The 400m specialist, who has linked up with Nelson Mandela University this year, comes with a strong pedigree having represented South Africa at the World Junior Championships in Colombia last year.
With that experience under his belt, he has set his sights on an upward curve in his career with the move to Madibaz a key part of the plan.
"In the past my mother played a big role in my training while my coach, Gerrie Posthumus, is always there with advice and programmes," said the 18-year-old, who was born and bred in Hopetown in the Northern Cape.
He acknowledged the support from his family in his formative years but knew he had to take the plunge to chase his dreams of making an impact on the national and, eventually, international stage.
"I'm excited about coming to Madibaz and look forward to quality training sessions with the group to allow me to go a step further in my career."
Van der Walt, who placed third at the national U20 championships and fourth in his heat in the world event last year, has been drafted into the national senior squad from which the final team for the world champs in Hungary in August will be chosen.
The sport had been in his blood since before his competitive days at the Hopetown junior and high schools, he said.
"Our whole family loves athletics. My mother and father did athletics when they were younger and that was passed on to my sister and me.
"It has been part of my life for as long as I can remember but when I started school and began racing I knew that I loved it."
Van der Walt learnt to sprint the hard way – on a gravel track at school. And, naturally, when Covid struck a gravel track was constructed on the family farm to allow his training to continue.
His first taste of tartan was as an 11-year-old when he started competing in "bigger" age group competitions around the country.
In 2020, Van der Walt was selected for the African Youth Games in Lesotho before Covid put a premature end to it. Last year, he was chosen for the World Junior Champs in Cali, Colombia, as well as for the African Youth Games in Malawi.
He trained twice a day – both on the track and in the gym – and paid a lot of attention to his technique to allow him to continue his development, he explained.
Blessed with a strong will, he said he was no stranger to putting in the hard yards when he had put his mind to something. One of his goals this season is to steer clear of niggles and injuries.
Madibaz Sport athletics manager Bernard Petersen said the club was delighted to have the speedster on board.
"It is so rewarding to have an athlete such as Tjaart in the squad. His presence has already made a huge impact; you can pick it up among his peers."
He felt that Van der Walt would be a good investment as they headed into Varsity Athletics and a number of other important events.
In what he termed a promising sign, Petersen said Madibaz Athletics had been inundated with requests by athletes from outside the metro to join the club.