(Senior / Principal) Scientist, Peptide Chemistry (Night Shift)

Capable Labs • San Francisco, CA

2d • Onsite

About The Position

We are a vibrant and intensely mission-driven team in San Francisco, comprising members from MIT, Harvard Medical School, Roche, ETH, and Dana-Farber. We value speed and rigor, coupled with excitement, drive, and a strong work ethic. In an early-stage environment, we value people who can bring clarity to open-ended problems, take ownership of the next steps, and follow through with energy. Capable Labs is a place for ambitious, high-integrity people who want to become dramatically better. You will be surrounded by people who care intensely about the work, get close feedback from the people making scientific and company-defining decisions, and have room to own increasingly important problems. We believe excellent work should be met with meaningful reward, ownership, and trust. Responsibility is earned through contribution, not title alone: anyone who demonstrates the judgment, rigor, and follow-through to move important work forward can earn meaningful scope. About the Role You will lead peptide-chemistry execution on a dedicated night-shift schedule, keeping synthesis, purification, characterization, and biological handoffs moving around the clock. You will make sound technical decisions independently, solve difficult chemistry and instrument problems, and ensure the day team receives complete, decision-ready work each morning.

Requirements

• Able and willing to work the designated night-shift schedule reliably and make consequential technical decisions independently when needed.
• Five or more years of hands-on industry experience in peptide, medicinal, organic, or closely related chemistry.
• Strong synthetic-chemistry fundamentals, experimental judgment, and deep troubleshooting ability; direct peptide experience is helpful.
• Experience owning chemistry end to end, including design, synthesis, purification, characterization, quality control, and preparation for biological testing.
• A fast, rigorous, and safety-conscious working style with excellent experimental records.
• The ability to lead through technical judgment and create clean, useful handoffs across night and day teams.

Responsibilities

• Lead overnight peptide synthesis from route or sequence planning through reaction setup, solid- or solution-phase synthesis, cleavage, purification, characterization, and sample preparation.
• Run and optimize microwave-assisted solid-phase peptide synthesis, including resin loading, coupling and deprotection cycles, crude analysis, and final quality control.
• Resolve difficult overnight issues involving failed reactions, low conversion or purity, side products, solubility, cleavage or deprotection, purification, and instrument downtime.
• Purify and characterize compounds using analytical HPLC, prep HPLC, LC-MS, NMR, and related methods as appropriate.
• Own identity, purity, yield, analytical traces, batch records, and sample readiness for in vitro and in vivo testing.
• Contribute chemistry insight on feasibility, SAR, stability, solubility, yield, and structure-property relationships to guide the next compounds.
• Provide disciplined morning handoffs covering results, failures, technical decisions, sample locations, risks, and follow-up actions.

Benefits

• Generous equity options
• $500+ monthly wellness budget for training, supplements, coaching, recovery, or other tools that help you perform at your best.
• Medical, dental, and vision coverage options, with Capable covering 100% of the base policy.
• HSA, FSA, and 401K plans.
• Healthy dinners with the team are provided daily.
• Visa sponsorship where appropriate, including O-1, H-1B, J-1, TN, and other employment-based pathways.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed