Scientist / Senior Scientist, Organic Chemistry
Summary
Scientist/Senior Scientist role at a stealth biotech startup designing and executing synthetic routes for small-molecule and peptide therapeutics, operating HPLC/LC-MS instrumentation and delivering purified compounds for biological testing in close collaboration with biology teams.
About the Role
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.
What You’ll Do
Lead organic chemistry execution across small-molecule, peptide, and peptide-adjacent programs, from target compound selection through route design, synthesis, purification, characterization, QC, and handoff for biological testing.
Design and execute synthetic routes using solid-phase and solution-phase workflows, including functional group transformations, coupling chemistry, protecting group strategies, late-stage diversification, cleavage and deprotection where relevant, purification, and analytical characterization.
Own compound preparation end-to-end. You are responsible for making the right molecules cleanly, confirming identity and purity, documenting the work clearly, and preparing material that is ready for biological testing.
Learn, operate, and help maintain key chemistry instrumentation, including HPLC, prep HPLC, LC-MS, microwave-assisted synthesis systems, and related analytical or purification platforms.
Troubleshoot synthetic and analytical issues with strong experimental judgment, including failed reactions, low conversion, poor selectivity, low crude purity, side products, solubility limitations, purification challenges, poor recovery, and instrument downtime.
Work closely with biology and pharmacology teams to understand which compounds matter next. Use SAR, potency, stability, exposure, tolerability, and efficacy data to help prioritize synthesis, but stay anchored in practical chemistry execution.
Who You Are
You have 5+ years of hands-on industry experience in synthetic organic chemistry, medicinal chemistry, peptide chemistry, or a closely related field. Peptide experience is helpful, but not required.
You have strong experimental judgment, deep troubleshooting ability, and a high bar for clean execution.
You are comfortable owning chemistry end-to-end: route selection, synthesis, purification, characterization, QC, documentation, and preparation for biological testing.
You have the judgment to turn a target structure into a confirmed compound. You can select a practical route, execute the chemistry, identify why reactions or purifications fail, make disciplined adjustments, confirm identity and purity, and deliver material ready for biological testing.
You are comfortable working close to biological readouts. You do not need to be the biologist, but you understand that chemistry decisions are made in service of potency, stability, exposure, tolerability, and efficacy.
You are proactive and reliable when issues arise. When a synthesis fails, an instrument is down, purity is low, material is missing, or a handoff needs clarification, you diagnose the issue, communicate clearly, and drive toward a practical resolution.
Pay & Benefits
$145,000-$220,000 salary, plus equity options with an implied current value of approximately $50,000-$200,000 before exercise cost, taxes, dilution, and liquidity risk.
Compensation will depend on the skills, experience, and scope of impact you bring. If your background, experience, or compensation needs fall outside this range, we are still open to a conversation based on the scope and impact you could bring.
$500+ monthly wellness budget for training, supplements, coaching, recovery, or other tools that help you perform at your best.
Healthcare: We offer a broad range of medical, dental, and vision coverage options, with Capable covering 100% of the base policy.
You will also have access to HSA, FSA, and 401K plans.
Healthy dinners with the team are provided daily.
We support visa sponsorship where appropriate, including O-1, H-1B, J-1, TN, and other employment-based pathways. Our team is already international, with members from Canada, Pakistan, Germany, Austria, Switzerland, China, India, and the United States.
Application Process
Our process is fast, transparent, and personal. We care about getting to know the person behind the application.
Initial application
First phone screen
Second phone screen
In-person work trial in San Francisco: designed to give both sides a realistic sense of working together. Get to know the founding team!
Apply Today
Curious but not sure? Apply anyway. It takes 5 minutes, and you do not need to be actively job searching to start a conversation.
Some of the best people do not map perfectly to a job description. If this sounds like a place where you could do important work, we would like to hear from you.
And if someone exceptional comes to mind, send them our way here. We read every referral carefully, and if your referral joins Capable, we’ll send you a thank-you bonus.