Sr. Scientist- Mechanistic Biology; Oncology

Our Bay Area client is a growing biotechnology company seeking a Senior Scientist to join its Mechanistic Biology group and drive discovery efforts for next‑generation targeted oncology therapeutics. This is an opportunity to work at the intersection of natural product chemistry, ADC payload innovation, and mechanistic biology, contributing directly to programs advancing toward the clinic.

You will lead the design and execution of biochemical and cell‑based assays that uncover mechanisms of action for novel cytotoxic payloads. Your work will shape structure–activity relationship (SAR) campaigns, guide medicinal chemistry optimization, and illuminate how new payload classes behave in relevant biological systems. The role is highly collaborative, hands‑on, and central to scientific decision‑making across multiple discovery programs.

• Develop and execute mechanistic cell‑based and biochemical assays to characterize novel payload classes.
• Build assays that generate quantitative, mechanistically interpretable data to support SAR and medicinal chemistry efforts.
• Investigate payload activity, selectivity, and resistance mechanisms to inform program strategy and prioritization.
• Integrate omics‑driven insights in partnership with computational biology colleagues.
• Collaborate closely with chemistry, ADC engineering, protein science, and cell biology teams to ensure biological relevance.
• Analyze complex datasets and translate findings into clear, actionable recommendations.
• Present results and strategic implications to cross‑functional teams and scientific leadership.
• Maintain high‑quality experimental documentation and uphold strong laboratory and safety practices.
• Contribute to a culture of scientific rigor, transparency, and collaborative problem‑solving.

• PhD in Biochemistry, Cell Biology, Biophysics, Pharmacology, Chemical Biology, or related field, with 3–5+ years of industry experience.
• Demonstrated experience elucidating mechanisms of action for small molecules or cytotoxic agents.
• Strong hands‑on expertise with cell‑based mechanistic assays relevant to oncology or targeted therapeutics.
• Flow cytometry expertise is required.
• Experience developing biochemical assays that support SAR is a plus.
• Background with ADC payloads, cytotoxic compounds, or targeted oncology modalities is highly desirable.
• Proven ability to think mechanistically, design creative assays, and solve complex biological problems.
• Strong communication skills and experience influencing cross‑functional decisions.
• Highly collaborative, proactive, and motivated by scientific discovery.

This position offers scientific ownership, cross‑disciplinary collaboration, and the chance to shape the trajectory of innovative oncology programs built on natural‑product‑derived payloads. It’s a strong fit for scientists who thrive in fast‑paced discovery environments and enjoy translating mechanistic insights into therapeutic impact.