Scientist / Senior Scientist, Organic Chemistry

About the Role You’ll work closely with the founders and a small team from MIT, Harvard Medical School, Baker Lab, and Radical Numerics. The pace and scope of the work create a substantial opportunity for growth. We are looking for speed and rigor, coupled with excitement and drive. 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. We believe excellent performance and excellent output should be met with meaningful reward and ownership. At Capable, that means anyone who proves they can drive work forward can lead important programs, from senior scientists to junior scientists. 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 for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. We sponsor visas, if necessary. Wellness budget: $500 per month to spend on training, supplements, personal trainers, and everything you need to become your best self. Healthcare: We offer a range of comprehensive medical options, so you can choose the plan that best fits your needs. Application Process Initial application First phone screen Second phone screen, approximately 30 minutes In-person work trial in San Francisco Apply Today Applying takes 5 minutes and we encourage you to apply as soon as possible. We're evaluating candidates on a rolling basis and want to make an offer quickly.