Melfi Dermaku emerged to the senior team in the beginning of the 2011–12 season, where he made his professional debut on 30 October 2011 in the matchday 13 against
Celano, playing the last 13 minutes of a 4–0 home triumph. Later on 4 December, Dermaku made his second appearance of the season as well as his first start in a 3–1 away defeat to
Paganese. He finished his first senior season by making eight league appearances, as
Federiciani finished the season in 16th position in Lega Pro 2. In his last season the 2014–15, Dermaku was named as a team
captain. On 1 April 2015, Dermaku made his 100th league appearance for the club by scoring in Melfi's 2–3 away win over
Casertana.
Empoli On 15 May 2015, Dermaku completed a transfer to
Empoli by penning a three-year contract with the
Serie A club. He was seen as a replacement for
Daniele Rugani which left for
Juventus.
Cosenza On 31 August 2017, after he become a free agent following the departure from Empoli, Dermaku joined
Cosenza on a two-year contract. He made his debut for the club on 9 September in the goalless draw against
Matera, while his first goal came on 31 March of the following year in the 2–1 win at
Juve Stabia. Dermaku concluded his first season by making 40 appearances in Serie C, all of them as starter, collecting 3555 minutes;
Rossoblù achieved their promotion to
Serie B for the first time in 15 years. Even after the club returned in Serie B, Dermaku was able to retain his place in the starting lineup, making 33 appearances in the
2018–19 season. His debut in the league came in the opening matchday against
Ascoli which ended in a 1–1 draw at
Stadio Cino e Lillo Del Duca. On 22 April 2019, he scored his first Serie B goal, the winner against
Spezia at home. Following the end of the season, Dermaku become free agent after his contract expired and he decided not to renew it. He concluded his spell with Cosenza by 79 matches between league and cup, scoring twice in the process.
Parma On 7 July 2019, Dermaku signed a four-year contract with top flight side
Parma.
Lecce On 5 October 2020, he was loaned to
Lecce for the 2020–21 season. On 30 August 2021, he moved to Lecce on a permanent basis and signed a three-year contract. ==International career==