Halimi first played for a local club VfL Germania 1894 and joined the youth academy of Eintracht Frankfurt, when he was six years old.

[5] On 13 July 2017, he made his debut with Brøndby in the 2017–18 UEFA Europa League second qualifying round against the Finnish side VPS after coming on as a substitute at 64th minute in place of Kamil Wilczek.

[8][9] Three days later, he made his debut in a 2–2 home draw against Midtjylland after coming on as a substitute at 76th minute in place of Lasse Vigen.

[12] He scored his first goal for Sandhausen against Holstein Kiel on 22 December, exploiting a poor pass from opposing goalkeeper Dominik Reimann in an eventual 2–2 draw.

[13] On 23 December 2020, in the second round of the DFB-Pokal, Halimi made his cup debut for Sandhausen, coming off the bench at half-time for Julius Biada as they were knocked out 4–0 by VfL Wolfsburg.

[15] During his two seasons with Sandhausen, Halimi made 27 total appearances in which he scored two goals, as he failed to become an established starter.

[17] Five days later, he made his debut in a 2–3 away win against Spartaks Jūrmala after coming on as a substitute at 66th minute in place of Felipe Brisola.

On 7 October 2015, he received a call-up from Kosovo for the friendly match against Equatorial Guinea,[21] and made his debut after being named in the starting line-up.