[1][2] Valderrama began his career in 1988 as a staff attorney for the United States Bankruptcy Court for Northern Illinois, where he worked for a year.

Starting in 1993, he then worked at Sanchez, Daniels & Hoffman in Chicago, where his practice focused on trial litigation.

He has also served as an adjunct professor at UIC John Marshall Law School, where he taught pre-trial civil litigation.

President Trump nominated Valderrama to the seat vacated by Judge Rubén Castillo, who retired on September 27, 2019.

[6] On September 17, 2020, the United States Senate confirmed his nomination by a 68–26 vote, with a majority of Republicans opposed and all Democrats in favor.