She has a career-high singles ranking of world No. 112, achieved on 15 March 2021. On the ITF Junior Circuit, Cocciaretto had a career-high combined ranking of 17, achieved on 5 February 2018. She reached the semifinals of the 2018 Australian Open girls’ singles tournament, losing to eventual champion Liang En-shuo.
Arruabarrena is coached by Andoni Vivanco. Her father, Juan, is a lithographer, and her mother, Blanca, is a nurse. She also has one younger sister. Arruabarrena started playing tennis at age of eight when took lessons with a friend for fun. She stated that her favourite surface is clay. When she was 15, she moved to Barcelona to train with Spanish Federation. Her tennis idol growing up was Justine Henin. Her favourite city is birthtown of San Sebastián, Spain. Arruabarrena made her debut appearance at the ITF Circuit at Les Francqueses del Valles, France, where she lost in first round against her compatriot Lucia Cervera-Vazquez, in straight-sets.