Sr. Data Scientist, Assay Development

About Us DELFI Diagnostics, Inc. (DELFI Diagnostics) is developing next-generation, blood-based tests that are reliable, accessible and deliver a new way to help detect cancer. Employing advanced machine-learning methods to whole-genome sequencing data, the DELFI ("DNA EvaLuation of Fragments for early Interception") platform is built to address the highest-burden health challenges. DELFI Diagnostics prioritizes solutions that have the potential to save lives on a global scale, including for historically underserved populations. DELFI Diagnostics’ platform relies on fragmentomics – the discovery that cancer cells are more chaotic than normal cells and, when they die, leave behind tell-tale patterns and characteristics of cell-free DNA (cfDNA) fragments. FirstLook Lung, for individuals eligible for lung cancer screening, is DELFI Diagnostics’ first laboratory-developed screening test and can be part of routine blood work. FirstLook Lung uses millions of data points to reliably identify individuals who may have cancer detected through low-dose CT, including early stage disease with a negative predictive value of 99.8 percent. This test has not been cleared or approved by the FDA. In our passionate pursuit to radically improve health outcomes, we serve humanity when we: Lead with Science, Anchor in Pragmatism: We pioneer life-changing science by ensuring quality, transparency, and rigor at all times. We explore thoughtfully, experiment smartly, and deliver impact with conviction. Build With & For All: We embrace diverse backgrounds to innovate and achieve together. We are not just building a product - we aim to disrupt the path of cancer for all - no matter geography or socioeconomic class Put We over I: We are a home for high-performing people. Through teamwork, we build collective intelligence. Each of us wins when those we serve and those who serve with us--win. We show up with empathy, humility, and integrity at every step of the journey. DELFI has 1-2 designated in-office working days each week for employees who live within within 50 miles of Palo Alto, CA About the Role The Senior Data Scientist will partner with assay development, lab operations, quality, regulatory, and software teams to support DELFI’s LDT and IVD early cancer detection assays as they move from late development into commercial use. The role focuses on study design and data analysis that keep our products performing reliably, including performance monitoring frameworks, change impact assessments, and bridging studies for LDT updates, as well as supporting verification and transfer to production. As products evolve, this person will also contribute to assay development work. The ideal candidate brings strong statistical foundations, experience in regulated diagnostics, and the ability to work independently across the later stages of the product lifecycle. What You'll Do Design studies and analyze data to evaluate assay performance and inform product decisions. Develop statistical methods for production monitoring and for qualifying reagents, controls, and instruments across LDT and IVD products. Assess the impact of reagent, instrument, software, and process changes, and design and analyze bridging studies for LDT updates. Support verification and transfer to production for LDT and IVD products, including defining acceptance criteria. Support regulatory submissions (CLIA/CAP, NYS, FDA as applicable) with rigorous, well-documented analyses. Lead data analysis for troubleshooting, investigations, and root cause analysis, and contribute to assay development as products evolve. Produce well-documented code (Python preferred, R acceptable) that meets quality system and software team standards. What You'll Bring Required Master’s degree in Statistics, Biostatistics, Applied Math, Bioinformatics, Engineering, or a related quantitative field; PhD preferred. Five or more years of experience in scientific data analysis, including at least three years in Python or R (Python preferred). Strong foundations in probability theory and statistics, including hypothesis testing, confidence intervals, parameter estimation, equivalence testing, and variance components. Experience in a regulated diagnostics environment (IVD, LDT, or similar), including designing, analyzing, and documenting verification, validation, or change assessment studies. Demonstrated ability to independently lead study design and analysis with cross-functional teams. Ability to connect assay chemistry to data behavior to troubleshoot performance issues. Familiarity with Design of Experiments and related quality methods (statistical process control, measurement systems analysis, Six Sigma/DMAIC). Preferred Experience supporting launched assays, including production monitoring, lot qualification, or post-market changes. Experience supporting assay transfer from development into production or a clinical laboratory. Exposure to NGS-based assays, including sequencing QC and batch variability. Familiarity with FDA design controls and IVD submissions. We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.