Before law school, Walker Moller worked and volunteered for three years in 15 countries throughout Southeast Asia, Oceania, and Africa. While at Mississippi College School of Law, Walker clerked at the Mississippi Supreme Court and was on the Law Review. He graduated summa cum laude in 2014 and earned the highest grade in eight courses. After graduation, Walker clerked for a federal judge at the United States District Court, Western District of Louisiana, where he gained exposure to a large volume of employment discrimination matters, products liability cases, and constitutional litigation.

Walker then worked for the U.S. Army Corps of Engineers from 2015 to 2021, where his practice focused on federal contracts and civil litigation in various administrative courts. Immediately before joining Siri & Glimstad, Walker achieved full dismissal of a lawsuit against the Corps of Engineers that implicated $68M worth of federal contracts.