Brandon was born on 28 January 1993 in Bredene. After playing two years for Bredene, he joined the youth academy of Club Brugge. From the age of six, he progressed through all the youth teams of Blauw-Zwart. He is a prime example of a youth product of Club! He was trained as a right-footed center-back who can also play as a right-back. Additionally, he took the initiative to develop a strong left foot, making him ambidextrous.
Throughout his youth development, Brandon remained humble and earned his place in the first team through hard work, focus and ambition. In May 2013, he made his debut as a substitute against SC Lokeren. A week later, he came on as a substitute again, this time against Standard Liege replacing Jørgensen.
Mechele has become a key figure at Club Brugge. In September 2022, he extended his contract with Blauw-Zwart until 2025.