Principal Scientist, Protein Engineering & Manufacturing

Exthymic is an early-stage deep-tech startup on a mission to prevent millions of cancer deaths by making curative cell therapies widely accessible. Our platform enables patient-specific treatment manufacturing at the point of care, overcoming the limits of centralized biopharma models. Led by experienced industry pioneers, we blend hardware, software, and biological engineering to disrupt the status quo and democratize life-saving therapies. Join us to solve complex challenges and drive global healthcare innovation.

About You:

Reporting to the Chief Scientific Officer, you are the technical owner for the protein reagents within our consumables. You decide what we need, whether it is manufactured in-house or through partners, and how we make it reproducibly at the scale and quality a product requires. You are a deep expert who stays hands-on, guides a small group of scientists and research associates, and enjoys connecting protein science to a working instrument through consumables.

Key Responsibilities:

• Drive protein reagent development—Set the scientific strategy for proteins in our consumables, from selection and engineering through characterization.
• Develop protein development workflows—Drive discovery, engineering, and optimization programs, whether run in-house or with external partners.
• Build protein production and conjugation processes—Establish robust expression, purification, labeling, and conjugation methods, and scale them to supply the product.
• Establish protein QC and stability—Define specifications and analytical methods for identity, purity, activity, and stability, and drive lot-to-lot consistency.
• Manage CROs and manufacturing partners—Select and direct antibody-discovery, engineering, and protein-manufacturing partners; scope work, run diligence, and transfer methods while protecting our IP.
• Mentor and develop the team—Mentor scientists and research associates; set the standard for rigorous, well-documented work.
• Partner across the platform—Work with the surface, cell, hardware, and software teams so protein reagents and assay readouts fit together.
• Contribute to IP—Identify inventions and contribute to disclosures and patent filings.

• Ph.D. in biochemistry, protein engineering, molecular biology, immunology, or a related field, plus 6+ years of relevant industry experience (or equivalent).
• Hands-on leadership of antibody or protein engineering programs, from discovery or design through characterization.
• Deep experience with recombinant protein expression, purification, and analytical characterization.
• Experience with bioconjugation and labeling chemistries.
• A track record of taking a protein reagent or biologic from development into reproducible production, with defined specifications and QC.
• Experience managing CROs or external partners for antibody discovery, engineering, or production.
• Experience guiding or mentoring scientists and research associates.
• Comfortable in an early-stage startup with evolving priorities.

Preferred:

• Experience with antibodies or protein reagents for diagnostics, cell selection, or cell-therapy applications.
• Experience with protein immobilization on surfaces or biosensors.
• Experience applying computational or AI-assisted protein design.
• Familiarity with GMP or quality systems for reagents or biologics.

Competitive salary and benefits package, including Medical, Dental, Vision, and 401k match.

Salary Range: $170,000 - $210,000, commensurate with experience

Benefits: We offer our employees comprehensive benefits, including medical, vision, and dental coverage, as well as retirement savings plans. Optional benefits include accident and term life offerings.

Equal Employment Opportunity: Exthymic Corporation is an equal opportunity employer and is committed to creating an inclusive environment for all employees. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity or expression, national origin, ancestry, age (40 and over), disability, medical condition, genetic information, marital status, military or veteran status, reproductive health decision-making, or any other characteristic protected by applicable federal, state, or local law. We comply with all applicable equal employment opportunity laws and will make reasonable accommodations for qualified individuals with disabilities throughout the application and employment process.

Agencies: We work directly with candidates and do not accept unsolicited resumes or referrals from recruitment agencies, search firms, or staffing companies. Any resumes submitted by an agency without a signed agreement in place will be considered the property of Exthymic and no fee will be owed. If you are interested in partnering with us on a future search, please contact our HR team directly.