Jacob Siar joined Northwestern University as an Assistant Coach for the swimming program in August 2023, following a highly successful five-year tenure at Army West Point.

From 2017 to the conclusion of the 2022-23 season, Siar served as the Associate Head Swimming & Diving Coach and Men's Recruiting Coordinator for the Black Knights. During his time at Army, the program experienced remarkable consistency and growth, with the men's team securing five consecutive second-place finishes and the women's team achieving three second-place finishes at the Patriot League Championships.

A highlight of his coaching career at Army was contributing to the men's team's historic dual meet victory over Navy during the 2022-23 season, a first for the program.

Siar is particularly recognized for his exceptional recruiting skills, evidenced by his success in attracting top-tier talent. He played a key role in bringing in swimmers such as Kohen Rankin, a SwimSwam "honorable mention" for the Class of 2022, and Johnny Crush, who was ranked by SwimSwam as the #10 recruit in the Class of 2024 – a significant achievement as the first non-Ivy League mid-major recruit to earn a top ten ranking.

Siar was a student-athlete and member of the swimming team at North Carolina State University from 2014-17. He graduated with a Bachelor of Science in Sport Management.