Before moving to academia, Michael Lewis spent twenty-five years in the computer industry, in a variety of technical, support, and management positions. He then ran his own consultancy in business communication for ten years, joining Macquarie University in 2001, initially to teach business communication and academic writing; he also lectured in theoretical linguistics, and was convenor of Macquarie's postgraduate programs in editing and publishing, before retiring at the end of 2013. His doctoral research project was an exploration of persuasion strategies in letters of complaint, and responses, in the computer industry. He served several terms in the positions of President and Secretary of the Australian Society for Technical Communication (NSW), and President and Vice President of the Society of Editors (NSW); he also served as a director of Australia's Institute of Professional Editors. He remains a Professional Member of the Society of Editors (NSW) and is a Life Member of the Australian Systemic-Functional Linguistics Association.
