As legal careers go, Ivan Fong, general counsel to 3M Co., has seen it all.

After clerking at the U.S. Court of Appeals for the D.C. Circuit and then at the U.S. Supreme Court for Justice Sandra Day O’Connor, he spent seven years at Covington & Burling. Fong later jumped to the U.S. Justice Department, where he served as deputy associate attorney general during President Bill Clinton’s final term. He would never look back at Big Law.