DJ was raised in Muskego, WI. As the youngest of six, he came from a very talented athletic family. His older brother and two sisters played college basketball, while his other two sisters played college volleyball.
As a player, DJ began his preps career at Muskego High School where he earned two Varsity Letters as a freshman and sophomore. While at Muskego, Mlachnik earned All-Southeast Conference honors both years, leading Muskego in scoring his Sophomore year as team MVP. For his last two years of preps sports, DJ Transferred to St. John's Northwestern Military Academy. At SJNMA, Mlachnik became standout in basketball, baseball, and football in the Midwest Classic Conference receiving numerous All-Conference and All-Area honors. As a senior, he led the Lancers Basketball team to a 20-4 record and MCC Championship in 2011. DJ averaged 17.6 points, 7.1 assists, 5.2 rebounds per game while also receiving All-State Academic Honors. DJ currently holds SJNMA records in 3-point field goals made in a game (8), as well as 3-point field goals in a season (69).
Following one year of Post Graduate Basketball at SJNMA, DJ began his collegiate career in 2012 at a NCAA Division 1 school, University of Massachusetts Lowell. While a Riverhawk, Mlachnik had career highs of 19 points, 11 rebounds, and 5 assists respectively throughout his career. While at UMASS Lowell, DJ earned his undergraduate degree in 2015 from the university's School of Business, with a bachelors degree focused in Business Management. As a senior on the basketball team, DJ earned a graduate degree with his Masters of Business Administration in the spring of 2016.
After college DJ went on to consult with Basketball RAP as a Skill Development Trainer. Over the past year, he has trained over 150 athletes around the Milwaukee Area. Last fall, Mlachnik returned to his Alma Mater, SJNMA, where he became the Assistant Varsity Basketball Coach, under his father, Duane Mlachnik. He has also taken on the roles of Assistant Athletic Director and Phy Ed Strength Coach at the academy. In their first season as Coaches, the Mlachnik duo led a very young lancer team back to its winning tradition with a 12-11 record and what hopes to be a promising future ahead.
Duane is currently the head basketball coach at St. John’s Northwestern Military Academy. He is an alum of St. John’s Military Academy where he participated in two WISAA state tournaments. He continued his playing career at the collegiate level for NCAA Division II, St. Leo University. His love for basketball and desire to teach youngsters about the game while learning life lessons has brought him into coaching. He has 33 years of coaching experience and has coached at all levels of AAU and high school basketball. Duane has previously run summer basketball camps as a high school head coach for four years and has been involved with camps for 20+ years as an assistant high school coach. Duane believes that players must have dedication and a willingness to learn while having fun in a camp environment. His advice to his players is, “players who want reach their ultimate potential, put in more work than their opponent.”