Complex sentence: Pasternak began his career in 1979 at Spear, Leeds & Kellogg where he started as a librarian and eventually worked his way up to senior vice president, limited partner, and trading room manager.
Split into simpler sentences: Pasternak began his career in 1979 at Spear, Leeds & Kellogg where he started as a librarian. Pasternak eventually worked his way up to senior vice president, limited partner, and trading room manager.