Nunez-Alvarez most extensive and important accomplishments come from the 2023-24 season during his time at Virginia Tech as an assistant coach for the college team and the post grad group of professional swimmers during the 2023-2024 season. While working directly under the tutelage of Sergio Lopez Miro (First Olympic medalist for Spain in Swimming and 5x Olympic Coach), he was selected as a coach for the Mexican National Team at the World Aquatics Championships (Doha 2024), coaching 7 swimmers to 10 finals and 7 semifinals at the World Aquatic Championships (Doha 2024) and 3 semifinals at the 2024 Olympic Games in Paris, including 2 top 10 finishes. Additionally, 6 of his athletes were international medalists during the 2023/2024 season (Asian, Pan American Games, and SCM European Championships). Other accomplishments include several National and team records broken, highest place ever at the 2024 Men's NCAA Championships (tie, with a record of points), along several ACC medalists and Champions.

Nunez-Alvarez started his coaching career as an age group swim coach at Gulliver Swim Club in Miami. During his time there as the primary coach for the 11-12 Gold Group , the girls team won the FGC Junior Olympics meet in July 2019, while also qualifying several swimmers to the Southern Zone Meet as a part of the FGC team. As a graduate assistant at Delta State University for the 2021-2022 and 2022-2023 seasons, he helped the men’s team win their 5th and 6th NSISC conference titles in a row, breaking the school record for most titles won. Additionally, he coached several athletes to Division II All-American status. 

A native of Oviedo (Spain), Alvarez graduated with a Bachelor of Science in Exercise Science from Florida Southern College in 2018, and a Master of Science in Exercise Science and Kinesiology from Delta State University in 2023.

As a swimmer, Alvarez was an age group national champion in the 400 IM, 7 times Division II All-American in 200 fly, 200 IM, 400 IM, 200 and 400 Freestyle relays and team captain at Florida Southern in 2017.