Dr. Oranga is a retired Senior Lecturer in Organic Chemistry from the University of Nairobi and a former Consul General at the Kenya Consulate in Los Angeles, USA. She has extensive experience in the public sector, having worked at the Pyrethrum Board of Kenya in Nakuru, an organization that processes and markets pyrethrum-based products, a natural insecticide. She joined the Board as a Senior Chemist in charge of Research and Development before being promoted to Chief Chemist, becoming the first woman to lead a department at the organization.

Dr. Oranga also worked with the Commission for Higher Education in Kenya, the body responsible for coordinating university education in the country. In this role, she oversaw the Universities Accreditation section and was in charge of curriculum development for private universities in Kenya.

In terms of State Corporation Governance, she has served as a board member for several state corporations and educational institutions, including:

1. Kenya Medical Research Institute (KEMRI)- She served two terms and was involved in various committees, including chairing the Scientific Research and Innovation Committee, the Human Resource Committee, and the Finance and Development Committee.
2. Kenya National Archives Board.
3. Bondo Technical Training Institute- As chair of the Development Committee, she served two terms on the board and contributed to the Education and Audit Committees. Dr Oranga was also part of the team that mentored UGUNJA TVET from its inception and oversaw its development progress as the chair of the Development Committee.
4. Maseno School Board.
5. Patron of Atilili Schoolin Bondo and Nyatindo Schoolin Oyugis, Homabay County.
6. Currently, she serves as a Commissioner on the Homabay County Revenue Board, having been appointed in February 2023. In this position, she chairs the Human Resource Committee, where she has developed the board structure and charter. She is also responsible for overseeing the county health revenue stream and the Rachuonyo South sub-county.

Dr. Wenwa Oranga has received training on the expectations of the Board of State Corporations as outlined in MWONGOZO by the State Corporations Advisory Committee (SCAC). She has attended courses in Financial Management, Human Resources, Auditing, and Procurement Policies in Public Institutions. Additionally, she has been actively involved in devising, organizing, and conducting interviews for staff recruitment and promotions to senior positions within various organizations.

Her name is included in the Kenya Book of Records by Francis Wachira as the first Kenyan woman to obtain a doctorate in Chemistry.

Other notable engagements in Dr. Oranga's career include:

• Secretary for Maendeleo Ya Wanawake, a Kenyan national women’s empowerment body in Rachuonyo District.
• Board member of several schools, including Nyatindo Mixed Secondary School and Omboga Secondary School, and patron of Atilili Primary School and Ojuando Secondary School.
• Treasurer of the Nyanza Professional Caucus.
• Director at Pan African Petroleum.
• Trustee of the Jaramogi Oginga Odinga Foundation.
• Chairperson of the Staff Welfare, Agricultural Shows, and Student Guidance/Counseling Committee.

Dr. Oranga is also a member of various professional bodies, including the Natural Products Research Network for Eastern and Central Africa (NAPRECA), I.U.P.A.C., Kenya Chemical Society, the Technical Committee of the Nyanza Education Initiative, the Council of the Kenya National Archives, and the National Steering Committee for the Development of Science and Technology Parks.