After training in England, she returned to Uganda and worked in a variety of roles for the Ugandan Electricity Board, as well as editing the organisation's journal.

Whilst little is known about Muwanga's early life, she joined the Women's Engineering Society (WES) in 1965 as a graduate member.

[1] She was working at Associated Electronics Industries, which later became Metropolitan Vickers, as a special trainee, whilst studying at John Dalton College of Technology, now Manchester Metropolitan University, for a Higher National Certificate.

[3] Her obituary in The Woman Engineer stated that she chose electrical engineering over nursing as her career due to her "great desire to give herself to help others ... her country and her people".

[8] Whilst Proscovia Margaret Njuki is often described as Uganda's first female electrical engineer, Muwanga was active in the field several years earlier.