Senior Research Associate (CONTRACT CAMBRIDGE BASED)

Position Summary We are seeking a Senior Research Associate or Associate Scientist to join our Payload and Function team to support the development of a re-dosable and targetable platform for delivering diverse therapeutic modalities. This role is centered on designing and developing in vitro assays to support the functional evaluation and development of targeted delivery approaches. The ideal candidate brings deep expertise in cell-based and biochemical assay development, and can generate high-quality, decision-driving data of functional activity. Experience with or exposure to ADC or small molecule drug oncology research and development is particularly desirable. Experience with RNAi (siRNA, ASO, etc.) therapeutics also considered a plus. This is a highly collaborative hands-on role requiring scientific independence and a strong focus on building robust and predictive assays to drive platform development and candidate selection. Key Responsibilities Design and optimization of in vitro assays (cell-based and biochemical) to evaluate therapeutic function Establish and maintain relevant cell-based models Support development of quantitative and reproducible assay workflows to assess payload functional activity Generate high-quality datasets to drive candidate selection Collaborate cross-functionally with targeting, protein engineering, analytical, and translational teams to ensure assay outputs align with program needs Present data clearly and provide actionable recommendations to project teams Maintain rigorous experimental documentation and reproducibility standards Required Qualifications Senior Research Associate: B.S./B.A. in Biology or related field with +4 years experience in an academic or industry setting. MS degree considered a plus. Associate Scientist: B.S./B.A. in Biology or related field with 6+ years experience in an academic or industry setting or MS in Biology or related field with 4+ years in an academic or industry setting. Preferred Qualifications Industry experience in ADC or biologics discovery Industry experience in oncology drug discovery and development Industry experience with RNAi (siRNA, ASO, etc.) modalities Experience with targeted delivery systems or nanoparticles Experience supporting screening and ranking of conjugated molecules or biologics Familiarity with ligand-receptor biology Familiarity with cancer biology Experience with data analysis tools (e.g., Prism, FlowJo) Experience working in cross-functional drug discovery teams Key Competencies Strong experimental design and troubleshooting skills Experience in in vitro and biochemical  assay development and optimization Ability to generate quantitative, decision-driving data Clear scientific communication and data presentation Collaborative, execution-focused mindset with high attention to detail Flagship Pioneering and our ecosystem companies are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status.   Recruitment & Staffing Agencies: Flagship Pioneering and its affiliated Flagship Lab companies (collectively, “FSP”) do not accept unsolicited resumes from any source other than candidates. The submission of unsolicited resumes by recruitment or staffing agencies to FSP or its employees is strictly prohibited unless contacted directly by Flagship Pioneering’s internal Talent Acquisition team. Any resume submitted by an agency in the absence of a signed agreement will automatically become the property of FSP, and FSP will not owe any referral or other fees with respect thereto.   Offices: Cambridge, Massachusetts, United States (Ring Headquarters);