Senior Scientist, Peptide Chemistry (Night Shift)

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 Work a dedicated night-shift schedule, leading overnight chemistry workflows so compounds are ready for characterization, testing, or handoff the next day. Lead and execute synthesis across peptide, peptide-adjacent, and small-molecule programs, including route planning, reaction setup, solid-phase or solution-phase synthesis, purification, analytical characterization, and sample preparation. Run and optimize microwave-assisted solid-phase peptide synthesis where relevant, including resin loading, coupling/deprotection cycles, cleavage, crude analysis, purification, and final compound QC. Troubleshoot synthetic and analytical issues during night-shift hours, including failed reactions, low conversion, low crude purity, side products, solubility limitations, cleavage/deprotection issues, purification challenges, and instrument downtime. Purify and characterize compounds using analytical HPLC, prep HPLC, LC-MS, NMR, and related methods; record identity, purity, yield, analytical traces, and batch-level QC data for morning handoff. Prepare compounds for in vitro and in vivo testing, maintain rigorous experimental records, and communicate overnight synthesis results, issues, timelines, and risks clearly to the day team. Contribute to next-round compound design by sharing chemistry insight on synthetic feasibility, purity, yield, stability, solubility, and structure-property relationships. Who You Are You are specifically looking for or open to a senior night-shift lab role. You are comfortable working overnight hours, operating independently, making sound technical decisions, and handing off clean, well-documented work to the day team. You have 5+ years of hands-on industry experience in medicinal, organic, peptide, or related chemistry, with strong experimental judgment, deep troubleshooting ability, and a high bar for execution. Peptide experience is helpful, but not required. You are excited to learn or deepen solid-phase synthesis while bringing strong synthetic chemistry fundamentals. You are comfortable owning chemistry end to end: compound design, route selection, synthesis, purification, characterization, QC, and preparation for biological testing. You move quickly while maintaining scientific rigor, clean documentation, and appropriate safety standards. You are proactive and reliable when issues arise. When a synthesis fails, an instrument is down, purity is low, or a handoff needs clarification, you help diagnose the issue, communicate clearly, and work toward a practical resolution. Pay & Benefits $200,000-$260,000 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. 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! #J-18808-Ljbffr Capable