Joachim started his professional career at the age of 18 for a small Italian cycling team, Sonego Sport, After racing with them for three months, he was noticed by a bigger, De Nardi who were interesting him. After riding with De Nardi for 3 years, he joined the Discovery Channel Pro Cycling Team and rode as a super-domestique for the team. He has competed in six Grand Tours, including the Tour de France (2000, 2002), the Giro d'Italia (2005), and the Vuelta a España (2001, 2003, 2004, 2005). Joachim tested positive for nandrolone in 2000, His career highlight is becoming crowned the 2003 Luxembourg National Road Race Champion and the 2004 Luxembourg National Time Trial Champion. In addition, Joachim became the first Luxembourger to wear the race leader's golden jersey at the 2004 Vuelta a España. Joachim wore the jersey for two days. In 2007, Joachim transferred to the Astana outfit, but left them after two seasons.