In 1985, Tim Kievits started his career as a biochemical technician at the Department of Human Genetics at the University of Leiden. While working at the university, he also completed his Masters's degree in Chemistry at the University of Utrecht. In 1990 he joined Organon Teknika’s nucleic acid diagnostics R&D group that specialised in HIV, CMV and HCV detection and held various research and managerial positions at this company. He left his last position as Director of Technology of the Nucleic Acid Diagnostics Business Area to spin out and develop an innovative microarray technology. 

In 2000, he founded PamGene, a science and technology-driven company in the multi-biomarker testing area specialising in protein activity measurements in model systems and clinical samples. As CEO of PamGene, he organised several finance rounds for Pamgene, securing investments from international venture capital funds and corporate, local and private funds. He built an experienced management team and developed the novel technology into a robust CE-marked system (PamStation® and PamChips®). 

From January 2013 to 2019, he served as director of Healthcare Innovation at Vitromics Healthcare Holding, the parent company of PamGene. In this position, he established Vitromics as a Companion Diagnostics company, leading the strategic development of PamGene towards complementary diagnostic tests in the clinic. In this period, he developed a keen understanding of the Dutch healthcare system, including the regulatory, health technology assessment and payer aspects. From January 2020 on, he co-build the not-for-profit Precision Medicine Institute Foundation (TOMi) and took up the responsibility of Chairmen of the Board in August 2020. This institute aims at combining the regional public and private forces towards patient-driven and fastest implementation of personalised medicine tools in standard care. Several innovative clinical trials have been initiated and are running. 

In March 2019, he founded the Precision Medicine Laboratory (PML), where he serves as General Manager. PML has developed new technologies to discover compounds focusing on use in a personalised medical setting. PML approach shortens the time from finding a compound to its use in the clinic. 

Tim Kievits contributed to an extensive number of patents and articles. He co-organised several (inter)national conferences and symposia and presented and chaired sessions on personalised medicine. As Chair of the Personalised Medicines Topic Group of the EuropaBio Association for four years, he developed a good understanding of the European Government organisation in Brussels. He participated in and presented at several EU advisory meetings.