We are seeking a Principal Scientist to lead the product development of reagents and workflows for a Quantum-Si protein sequencing platform. This role owns the technical strategy, team execution, and cross-functional delivery of an integrated reagent system - multiple functional proteins, buffers, and additives - that must be co-optimized with the instrument's flow cell surface chemistry, optical detection, and thermal control subsystems.

The successful candidate will manage a team of workstream owners to develop the sequencing reagent set, and will represent the reagent function on the cross-functional core team alongside leaders in Operations, Engineering, Systems Integration, and Marketing. This is a leadership role with substantial scientific, programmatic, and organizational impact.

As part of our team, your core responsibilities will be:

Scientific & Product Development Leadership

• Own end-to-end product development for an integrated reagent kit, including recognizer/binder mixes, conjugates, sequencing and wash buffers, quenchers, and supporting additives.

• Drive integrated optimization of multiple protein-based reagents and supporting chemistry to meet platform performance specifications in concert with flowcell surface chemistry, optics, and thermal control.

• Guide the team through the full Product Development Process (PDP): feasibility, design development, design verification, validation, and transfer to manufacturing.

• Identify and mitigate technical risk early; lead complex root-cause investigations using DOE and advanced statistical analysis.

• Author and review key technical documentation, including product requirements documents, design verification protocols/reports, and tech transfer packages.

• Contribute to the multi-year reagent innovation roadmap across current and future platforms.

Team Leadership

• Manage and develop teams responsible for distinct reagent classes (e.g., recognizer development, bioconjugation, buffer/additive optimization, assay and QC development).

• Set technical direction, prioritize across workstreams, allocate resources, remove barriers, and ensure accountability for milestone delivery.

• Mentor scientists and managers; build a culture of scientific and product development rigor, urgency, and cross-site collaboration.

Cross-Functional Program Collaboration

• Serve as the reagent function's representative on the platform core team, partnering with leaders in Instrument Engineering, Systems Integration, Operations/Manufacturing, Quality, and Marketing to align reagent design with platform-level requirements and commercial goals.

• Translate platform-level performance targets into reagent design requirements and verification criteria.

• Drive the cross-functional schedule for reagent design lock, design verification testing, manufacturing transfer, and commercial launch readiness.

• Coordinate the transfer of new proteins and dyes from upstream component-development teams and their incorporation into reagent designs.

Qualifications

• PhD in Chemistry, Biochemistry, Molecular Biology, Bioengineering, or related field.
• 12+ years of relevant industry experience, including 8+ years in product development, with demonstrated leadership of reagent or assay development for a complex integrated product (instrument, consumable, and chemistry).

• Proven track record of successfully leading teams to launch one or more commercial products through a formal PDP, including design verification, validation, and transfer to manufacturing and QC.

• Direct experience in developing protein-based reagents and/or sequencing chemistry.

• Demonstrated experience leading other leaders (managing managers or senior ICs running workstreams).

• Strong working understanding of how reagents interact with optical detection, fluidics, surface chemistry, and thermal control subsystems.

• Expertise in DOE, statistical analysis of large datasets, variation analysis, critical parameter management, and root-cause investigation.

• Excellent written and verbal communication; able to operate fluidly between bench-level technical discussion and executive-level program communication.

• Demonstrated ability to collaborate across scientific disciplines, functions, and organizational levels.

Preferred

• Expertise in enzymatic kinetics and developing kinetic assays.

• Experience operating in a regulated environment (ISO 13485, FDA QSR).

• Multi-site team leadership experience.

The estimated base salary range for this position in the United States is $175,000- $200,000. In addition to base salary, full-time employees are eligible to participate in Quantum-Si's discretionary annual bonus program and may receive equity awards as part of the total compensation package.

Actual compensation will be determined based on a variety of factors, including, but not limited to, the position level, relevant skills, knowledge, experience, qualifications, geographic location, internal equity, and market data.

Quantum-Si also offers a competitive benefits package designed to support employees' health, well-being, work-life balance, and family needs. Benefits include:

• Comprehensive medical, dental, and vision insurance coverage
• Health Savings Account (HSA) and Flexible Spending Account (FSA) options, where applicable
• Company-paid life and accidental death & dismemberment (AD&D) insurance
• Short-term and long-term disability coverage
• Employee Assistance Program (EAP) resources to support personal and professional well-being
• Discretionary paid time off and company-paid holidays
• Parental leave to support employees welcoming and caring for a new child
• 401(k) retirement savings plan with both pre-tax and Roth contribution options

Additional Information

Candidates must be authorized to work in the United States. Quantum-Si does not provide employment-based immigration sponsorship of any kind for this position, including support for applicants currently pursuing permanent residency (Green Card sponsorship).

Quantum-Si does not accept unsolicited agency resumes.