[2] As a senior at Baltimore's Archbishop Curley High School, Harty was named the 2014 Varsity Sports Network Offensive Player of the Year for football.

[5] That same year, Harty led the Friars to the Maryland Interscholastic Athletic Association (MIAA) B Conference Championship and their first undefeated football season in school history, which included a 28–0 shutout victory over traditional MIAA "A" Conference powerhouse Loyola Blakefield, a game in which Harty amassed 206 total yards (140 rushing, 66 receiving) with 2 touchdowns.

Assumption University career highlights: School records: Harty signed with the New Orleans Saints as a rookie undrafted free agent in 2019.

[8][9] After an impressive training camp featuring a 78-yard touchdown return against the New York Jets in the pre-season,[10] Harty made the final cut and was named to the Saints 53-man roster.

[11] Harty made his NFL debut on Monday Night Football as the Saints primary kick returner in the season-opener against the Houston Texans.

[24] He became one of the team's main kick returners, but also saw some action on offense, catching his first touchdown with the Bills against the New York Giants.

In week 18 against the Miami Dolphins, Harty returned a punt 96 yards for a touchdown, sparking a 4th-quarter comeback for the Bills as they would go on to win 21–14 and clinch the AFC East division title.