She qualified for all the apparatus finals and won silver in hoop and ribbon and bronze with clubs and ball.

[11] In the 2017 season, Kaleyn competed at the Moscow senior International Tournament, where she won silver in the all-around.

[12] She won bronze in the all-around at the 2017 Bulgarian National Championships behind Neviana Vladinova and Katrin Taseva.

She then competed at the 2017 Tashkent World Cup, where she finished 4th in the all-around behind teammate Katrin Taseva and qualified to three event finals.

On May 12–14, Kaleyn competed at the 2017 World Challenge Cup in Portimao, where she finished 4th in the all-around behind Victoria Veinberg Filanovsky.

She qualified to three event finals, where she won bronze in clubs and finished 5th in hoop and 6th in ball.

On March 23–25, Kaleyn competed at the 2018 Grand Prix Thiais, where she won the bronze medal in the all-around competition ahead of teammate Katrin Taseva.

On April 20–22, at the 2018 Tashkent World Cup, Kaleyn finished 9th in the all-around and qualified to two apparatus finals.

At her first World Championships, held in her hometown of Sofia, Kaleyn won a silver medal with the Bulgarian team.

[15] Kaleyn started her 2019 season competing at the GCP Lisbon senior International Tournament, where she ranked 5th in the all-around.

On April 16–19, she competed in the 2019 European Championships with her teammates Katrin Taseva and Neviana Vladinova, with whom she won the bronze medal in the team event.

[21] Kaleyn's routines for the 2024 season were unusual in that they were connected rather than separate and intended to portray the personal story of her career.

There she won the all-around ahead of fellow Bulgarian Stiliana Nikolova and Daria Atamanov.

[23] Both Kaleyn and Nikolova expressed gratitude for the supportive home crowd and stated that they were aiming to win gold at the upcoming 2024 Summer Olympics.

In the apparatus finals, she won gold in ball and ribbon and silver with hoop behind Sofia Raffaeli.

[26] At the European Championships, she ended in fourth place in the all-around after mistakes in her hoop and ball routines.

[30] At the last competition before the Olympics, the World Challenge Cup in Cluj-Napoca in July, she finished fourth in the all-around and qualified for three apparatus finals.

"[34] After the award ceremony, Iliana Raeva, the president of the Bulgarian Rhythmic Gymnastics Federation, called Kaleyn ‘The Queen’ and said she had never had such a successful competition, with eight out of eight routines performed with a high level of difficulty and without mistakes.

[37] At the same time, the Bulgarian Rhythmic Gymnastics Federation announced the final selection for the new individual national team.

[22][42][43] (Team competitions in seniors are held only at the World Championships, Europeans and other Continental Games.)