Scientist, Peptide Chemistry

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 make and characterize peptide candidates that move directly into biological testing. You will execute the full synthesis workflow—from resin loading through purification, quality control, and sample handoff—while troubleshooting failures and contributing observations that improve the next design cycle. This is a hands-on role for someone who wants close ownership of the molecules they produce. Responsibilities Execute end-to-end peptide synthesis workflows, including resin loading, coupling and deprotection cycles, cleavage, purification, analytical characterization, and sample preparation. Run microwave-assisted solid-phase peptide synthesis and support routine synthesizer maintenance. Troubleshoot failed couplings, low crude purity, side products, cleavage issues, and instrument downtime. Purify and characterize candidates using analytical HPLC, prep HPLC, LC-MS, and related methods. Record identity, purity, yield, analytical traces, and batch-level quality-control data before handoff. Prepare compounds for in vitro and in vivo testing and maintain accurate experimental records. Share synthesis feasibility, purity, yield, stability, and analytical observations that inform what the team designs and makes next. Ideal Qualifications Hands-on chemistry experience and strong experimental discipline; your education path matters less than your ability to learn quickly and produce high-quality results. Interest in owning synthesis end to end: running reactions, purifying and characterizing compounds, documenting results, and preparing material for testing. A creative, fast, and rigorous approach to experimental problem-solving. Interest in staying close to biological readouts and understanding how potency and efficacy data inform the next design cycle. High agency when an instrument breaks, a synthesis fails, results look unusual, or a handoff is unclear. Experience with solid-phase peptide synthesis, HPLC, prep HPLC, or LC-MS is valuable, but we can teach specific workflows. Pay & Benefits In addition to the posted salary range, we offer generous equity options. 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. Equal Opportunity Capable is an Equal Opportunity Employer; employment with Capable is governed on the basis of merit, competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.