Walden has extensive experience as an instructor in accounting and taxation, both in the public and private sector. He has also written several books in the fields of accounting and taxation.

He previously worked at Aalto University’s Department of Accounting and in tax inspection functions at Finnish Tax Administration. He is a member of the Board of Directors at the Taxpayers’ Association of Finland. In 2003, Walden was named Teacher of the Year at Helsinki School of Economics.