About the roleTo help drive this innovation, we are seeking a highly motivated Sr. Scientist to lead protein engineering efforts in support of our platform. The successful candidate will design and execute engineering campaigns to improve the activity, stability, and manufacturability of the enzymes at the core of our technology - from library design and high-throughput screening through purification, characterization, and formulation. This role requires deep hands-on technical expertise, sound experimental judgment, and the ability to translate screening data into the next round of design.
This is an individual contributor position with no direct reports. The successful candidate will own their projects end to end at the bench, set technical direction within their area, and influence the broader team through scientific leadership, collaboration, and informal mentorship rather than through people management.
Key Responsibilities- Design and execute protein engineering campaigns to improve enzyme activity, specificity, thermostability, expression, and manufacturability against defined project objectives.
- Design and construct mutagenesis and combinatorial libraries, selecting appropriate diversification and selection strategies for each engineering goal (e.g., site-saturation, combinatorial, error-prone PCR, or computationally guided design).
- Build and run high-throughput screening workflows, including plate-based assays, automation, and liquid handling, to evaluate large variant sets efficiently and reproducibly.
- Develop, optimize, and qualify biochemical and biophysical assays to support screening and candidate characterization; troubleshoot assay performance and drive assays from concept to routine use.
- Lead formulation optimization for engineered proteins: screen buffers, excipients, and stabilizers to maximize activity retention, solubility, and shelf life; run thermal, freeze-thaw, and accelerated stability studies; and define storage and handling conditions that meet platform and product requirements.
- Express and purify recombinant proteins using chromatography techniques (affinity, ion exchange, size exclusion, hydrophobic interaction) on C4KTA and gravity column systems, and assess purity, identity, and quality using standard analytical methods.
- Analyze and interpret screening, characterization, and stability data; identify sequence-function and formulation-stability trends and feed them into subsequent design cycles.
- Maintain rigorous experimental documentation and adhere to SOPs and data integrity standards; contribute to protocol and SOP development as workflows mature.
- Communicate clearly in writing and verbally with cross-functional partners, present scientific findings at team meetings, and collaborate closely with molecular biology, protein production, analytical, engineering, and computational colleagues to keep projects aligned on timelines and deliverables.
Qualifications- Bachelors degree with 10+ years, Masters degree with 7+ years, or PhD with 3+ years of relevant industry or research experience.
- Degree in Biochemistry, Chemical Engineering, Molecular Biology, Protein Science, Biotechnology, or a related life sciences discipline.
- Demonstrated hands-on experience in: Protein engineering and library design; High-throughput screening of protein variants; Assay development and optimization; Protein formulation and stability optimization; Protein expression and multi-step chromatographic purification
- Strong written and verbal communication skills, with the ability to present complex data clearly to both technical and cross-functional audiences.
- Proactive team-player mindset, strong attention to detail, and the ability to work independently and prioritize effectively in a fast-paced environment.
- Familiarity with laboratory safety protocols and experience maintaining rigorous scientific documentation.
- Laboratory automation and liquid handling experience applied to screening workflows.
- Proficiency in data analysis and scripting, or familiarity with machine-learning-guided protein design.
- Experience mentoring junior scientists or leading a project workstream as an individual contributor.
Physical Demands & Work Environment- Work will be performed onsite in office and laboratory space located in South San Francisco.
- Mobility: Must be able to move about the laboratory and office environment regularly. This includes standing and walking for extended periods, often up to 6-8 hours per day.
- Manual Dexterity: Must have fine motor skills and steady hands to handle delicate instruments, operate laboratory equipment, pipette accurately, and perform repetitive benchwork with precision.
- Lifting/Carrying: Must be able to lift and carry up to 40 pounds occasionally, such as boxes of lab supplies or equipment.
- Visual Acuity: Must have sufficient visual acuity to read small print on labels, instrument displays, and computer monitors. Close vision, color vision, and the ability to adjust focus are required.
- Environmental Conditions: Frequently exposed to typical laboratory conditions, including biological samples, chemicals, and reagents. Must be able to wear appropriate personal protective equipment (PPE) such as lab coats, gloves, and safety goggles as required.
The pay range for this role is:
125,000 - 150,000 USD per year (HQ)
