Youth years Mulder was born in
Baarn, and is a product of
Feyenoord's youth academy. In 2004, he started playing for Feyenoord's satellite team
SBV Excelsior.
Excelsior Mulder made his debut in professional
football as part of the
Excelsior Rotterdam squad in the 2004–05 season. For two seasons there, he made 46 caps, scoring 4 goals.
RKC Waalwijk In 2006, Mulder started playing for
RKC Waalwijk. For five seasons he became an irreplaceable part of the right part of the defense, making 153 or more caps and scoring 4 goals. Mulder left Waalwijk at the end of the 2009–10 season, when his contract expired.
Levski Sofia On 30 June 2010, Mulder agreed to join Bulgarian side
Levski Sofia. On the following day he made his unofficial debut in a friendly against
Metalist Kharkiv, before signing a two-year contract on 2 July as a free agent. He made his competitive debut on 22 July in a 2–0 away win over
Dundalk in the second qualifying round of the
2010–11 UEFA Europa League. On 8 December 2011, Mulder signed a one-year contract extension, keeping him at Levski until 2013. He scored his first goal for Levski on 25 August 2012 in a 2–0 win against
Montana at the
Ogosta Stadium. In January 2013, it was reported that Mulder had extended his contract with Levski. The new two-year contract was signed on 15 January. Mulder ended 2012–13 season with a total of 5 goals. In the summer of 2013 he was temporarily released from Levski, but was reinstated to the first team a month later. In December 2013 during a game against
CSKA Sofia for the Bulgarian Cup, Mulder scored the last penalty for his team in the 7–6 win which led the team to the quarterfinals of the tournament. Mulder made his last appearance for Levski Sofia on 24 May 2014, after replacing
Elin Topuzakov in the first half of a 3–2 win over
Lazio in an
exhibition match held to commemorate 100 years of the founding of the "blues". In the beginning of June 2014, the newly appointed sports director of Levski announced that the "bluemen" would no longer use Dustley's services as a player. In his four years playing for the Bulgarian club, Mulder made 95 appearances and scored 2 goals.
Apollon Limassol In July 2014, Mulder signed a one-year contract with Cypriot club
Apollon Limassol, with an option for an additional year. He made his official debut on 21 August 2014, in the 1–1 home draw with
Lokomotiv Moscow in a
UEFA Europa League match after coming on as a substitute during the second half.
NAC Breda In July 2015, Mulder joined Dutch side
NAC Breda for one year, with the possibility of a second one. ==International career==