Donski has won 19 ITF Men's World Tennis Tour titles in doubles[4] and is an active member of the Bulgarian Davis Cup Team.

[5] In late 2016, Donski began a YouTube channel called Operation Liftoff that documented his progress at Futures tournaments on the ITF Pro Circuit as well as showcased some of the challenges and routines of a professional tennis player's life on tour.

[6] The channel was made in close collaboration with his cousin, Lazar Dokov, who traveled with and competed alongside him in Southeastern Europe until October 2017.

[25] Some of the more notable opposition he faced in 2017 who barred him from acquiring additional ATP points included Hubert Hurkacz,[26] Botic van de Zandschulp,[27] and Tallon Griekspoor.

[43] In 2020, along with many other players, Donski struggled to adapt to the challenges of traveling and competing at professional events under the changing realities and restrictions of the COVID-19 pandemic.

[47] The most competitive singles match he played that year came in November at the second round of an M15 event in Antalya, where he clashed with recent ITF Junior No.1, Holger Rune.

[48] In doubles, Donski also found little success, making just a single semifinal appearance in October at an M15 event in Sharm El Sheikh.

[49] Despite these setbacks, his year-end ATP ranking for singles did not change substantially (ended No.596[50]), as two temporary special provisions across the tour were in place at the time.

One was a freeze of ATP points won in 2019 to account for disruptions in the regular event calendar by the pandemic,[51] while the other was related to ongoing experimental structural changes in the ranking system by the ITF.

He pulled an upset win over eighth seed Jurij Rodionov 2-6, 6-1, 7-6(4)[59] before losing in the final round to the Italian veteran, Andreas Seppi 2-6, 3-6.

[60] He also played in the doubles competition at his home ATP tournament with Dimitar Kuzmanov, but the Bulgarian duo lost in a third set tiebreaker to eventual champions Jonny O'Mara and Ken Skupski.

One month and a half later, however, Donski would return to Monastir to compete at another M15 event and this time would indeed emerge victorious, picking up only his second ever ITF Men’s World Tennis Tour singles title.

[78] Interestingly enough, Donski accomplished this with six different partners[79] (Théo Arribagé, Zvonimir Babić, David Pichler, Karl Friberg, Vladyslav Orlov, and Tim Sandkaulen) reinforcing his claim as a highly adaptable player in the game of doubles.

This versatility also manifested itself in a strong 6-3, 7-6(6)[80] victory over the South African team of Raven Klaasen (former ATP no.7 in doubles) and Lleyton Cronje Davis Cup competition in September back in Bulgaria.

In addition, Donski made good use of another wildcard at the ATP 250 event in Sofia by defeating the team of Fabrice Martin and Aisam Qureshi (a former top 10 doubles player) 4-6, 6-3, 10-8[81] alongside his countryman, Alexandar Lazarov.

[92] In 2024, Donski accelerated his trajectory as a doubles specialist on the ATP tour and vastly outdid any of his performances in previous years by capturing seven ITF titles across tournaments held in Portugal, Tunisia, and Spain.

In singles, despite obstacles posed by his lower ranking earlier in the year, Donski found some surprising success at three consecutive ATP Challenger 50 events that took place over the summer.

In Pozoblanco, he handily defeated Ulises Blanch 6-3, 6-1 in the first round before narrowly falling to second seed and former top 100 player, Egor Gerasimov, 6-4, 3-6, 4-6 after having led 3-0 with a double break in the final set.

In the third Challenger 50 event that he played (a second tournament in Dobrich), he received a wildcard into the main draw that he made good use of by reaching the quarterfinals.

[93] Shortly thereafter, in early February, he was summoned by the Bulgarian Davis Cup Team to play doubles in a World Group I tie against Romania where he and his partner Pyotr Nesterov delivered a critical 6-3, 6-3 victory over Victor Vlad Cornea and Gabi Adrian Boitan.

[97] His most notable wins came partnering Alexandar Lazarov against South Africa’s Raven Klaasen / Lleyton Cronje (6-3, 7-6) in 2022[98] and against the Kazakh team of Alexander Bublik / Aleksandr Nedovyesov (6-3, 6-3) in 2023.