Arambarri was born in Salto, and joined Defensor Sporting's youth setup in 2011 after impressing in a local youth tournament.[2] He was promoted to the first team in July 2013 by manager Tabaré Silva, and made his professional – and Primera División – debut on 15 September by starting in a 1–0 home win against Fénix.
Arambarri continued to feature regularly for La Viola in the following seasons, and scored his first senior goal on 21 March 2015 by netting the first in a 1–1 home draw against Cerro.[3]
Arambarri was only rarely used by the club in the 2016–17 campaign, being limited to four league appearances, all from the bench.
Getafe
On 9 August 2017, after having his federative rights assigned to Boston River,[6] Arambarri signed a one-year loan deal with La Liga club Getafe CF, with a buyout clause,[7] which was activated on 11 June 2018. Arambarri signed a five-year contract.[8]
On 18 September 2020, Arambarri was included in Uruguay's 26-men preliminary squad for World Cup qualifying matches against Chile and Ecuador.[10] He was later included in the final squad and made his senior debut on 8 October 2020 in Uruguay's 2–1 win against Chile.[11]
^"Match – Bordeaux chute à Lyon [3–0]" [Match – Bordeaux lose to Lyon [3–0]] (in French). Girondins de Bordeaux. 3 February 2016. Archived from the original on 10 March 2016. Retrieved 11 August 2017.