In July 2015, Ruse made her WTA Tour main-draw debut as a wildcard at the Bucharest Open in the doubles event, partnering Jaqueline Cristian.

She lost the first one to Claudia Giovine in straight sets, snapping her 14-match winning streak in singles, and in the second one she beat Julia Grabher.

After taking time off for her high school graduation, Ruse returned to competition in June at the $50k event in Essen, Germany.

As the last direct acceptance, Ruse shocked top seed Aliaksandra Sasnovich in three sets for her first win over a top-100 player.

Due to rain delays in Essen, she had to play her second-round match the same day and lost in straight sets to qualifier Olga Sáez Larra.

She reached her first WTA tournament final at the 2019 Bucharest Open, partnering again with Jaqueline Cristian; they were defeated by Viktória Kužmová and Kristýna Plíšková in the championship match.

Ruse won her maiden WTA Tour singles title at the Hamburg European Open, defeating Andrea Petkovic in the final.

[1] Following her run in Hamburg, Ruse reached a second consecutive final later that month, at the Palermo Ladies Open; however, she lost it in straight sets to Danielle Collins.

[6] At the 2024 French Open, she reached the doubles semifinals for the first time at this Major, partnering again Marta Kostyuk, with wins over ninth seeds Leylah Fernandez and Erin Routliffe, and then Mirra Andreeva and Vera Zvonareva by walkover.

122, she qualified for the main draw at the US Open defeating Julia Grabher and then upsetting eighth seed Barbora Krejčíková, her second top 10 win, to reach the third round of a major for the first time in her career.

[citation needed] Alongside Monica Niculescu, she won the doubles at the Hong Kong 125 Open in October, defeating Nao Hibino and Makoto Ninomiya in the final.

[12] Partnering Monica Niculescu, Ruse won the doubles title at the WTA 125 Open Angers Arena Loire, defeating Belinda Bencic and Celine Naef in the final.