Sebastián is a senior associate and a member of the corporate/M&A, capital markets, and banking & finance areas. He is also a member of the consumer law practice and specializes in corporate transactions, restructurings, international financings, and in massive consumption of goods and services matters.

Sebastián has been the Director of the América Solidaria Foundation since 2023, and in the academic field, he served as assistant professor in Administrative Law at the Pontificia Universidad Católica de Chile between 2017 and 2018.