Complex sentence: Paul T. Armstrong remains the longest working employee of Encyclopædia Britannica, beginning his career at Encyclopædia Britannica in 1934, eventually earning the positions of Treasurer, Vice President, and Chief Financial Officer in his 58 years of work at the company, retiring in 1992.
Split into simpler sentences: Paul T. Armstrong remains the longest working employee of Encyclopædia Britannica. He began his career there in 1934, eventually earning the positions of Treasurer, Vice President, and Chief Financial Officer in his 58 years with the company, before retiring in 1992.