Senior or Principal Scientist

Corsalex is a discovery-stage biotech in Sunnyvale, CA building a portfolio of programs targeting C9orf72-driven amyotrophic lateral sclerosis and frontotemporal dementia. We operate as a small, technically dense team running multiple programs in parallel. We move at the pace of a small biotech and seek high autonomy, fast iteration, and direct lines from hypothesis to data to decision.

Note: To apply for this role please email a resume and cover letter to View email address on click.appcast.io and include "Corsalex Scientist Position_Your Full Name" in the email subject line.

The Role

We’re hiring a Senior or Principal Scientist to own biology and disease modeling end-to-end across our C9‑ALS/FTD portfolio. This is a hands‑on bench role based in Sunnyvale, CA with full project ownership: you design and run the experiments, interpret the data, and shape program direction. You’ll work directly with our management team and mentor a junior scientist on the bench.

This role suits a wet‑lab biologist who has completed a postdoc, is familiar with the C9 literature, and is ready to take ownership of program development.

Responsibilities

• Design, execute, and interpret experiments in C9‑ALS/FTD‑relevant cellular models, including iPSC‑derived systems.
• Lead one or more discovery programs end‑to‑end, from target or mechanism hypothesis through assay development, compound or modality testing, and go/no‑go decisions.
• Develop and validate cellular assays for target engagement.
• Mentor a junior scientist; set lab operations and workflow standards across the team.
• Synthesize internal and external data into clear scientific arguments, written and verbal, that drive program decisions.
• Identify gaps, propose new approaches, and drive them forward.
• Clearly communicate timelines, deliverables, and lab outputs.

Qualifications

• Ph.D. in Cell Biology, Neurobiology, Molecular Biology, or a related discipline, plus a postdoc in a neuroscience lab.
• Strong experience in ALS/FTD biology and relevant cellular model systems; direct C9‑ALS/FTD experience is strongly preferred.
• Hands‑on expertise with iPSC‑derived neuronal differentiation, characterization, and phenotypic assay development.
• Proficiency in molecular cloning, lentiviral vector construction, and standard biochemistry (Western blot, IP, basic protein work).
• Demonstrated ability to operate independently, to scope a problem, design the experiments, troubleshoot, and reach defensible conclusions without close oversight.
• Experience mentoring or directly supervising junior scientists or technicians.

What We Look For

• You take initiative and don't wait to be told what to do.
• You’re comfortable working alone but value collaboration and reaching out when you need to.
• You speak up, even when you disagree.
• You’re curious and want to understand how things actually work.
• Low ego, high ownership.
• You’re adaptable when programs shift or priorities change.
• You’re organized, communicative, reliable, and committed to high‑quality science.
• Base salary contingent on candidate’s background and experience
• Equity
• Matching 401(k)
• Paid time off
• All eligible employees may also enroll in medical, dental, and retirement savings plans

Applicants must be authorized to work for any employer in the U.S. We are unable to sponsor or take over sponsorship of an employment visa at this time.