Senior Scientist, Protein Engineering

Flagshippioneeringinc
Flagshippioneeringinc logo
Location
Cambridge, MA USA
Job Type
Full-time
Posted
June 16, 2026
Views
9
Salary Range
$126k - $182k USD

Job Description

Company Summary:

Serif Biomedicines, Inc. is a privately held, early-stage biotechnology company developing a novel approach to gene therapy that can address currently untreatable diseases.

Serif Biomedicines was founded by Flagship Pioneering, an innovation enterprise that conceives, creates, resources, and grows first-in-category life sciences companies.

Flagship Pioneering has created over 100 groundbreaking companies over the past twenty years, all of which are pioneering novel and proprietary biological, industrial, and engineering approaches to solve major needs in human health and sustainability. These companies include Moderna (MRNA), Syros Pharmaceuticals (SYRS), Seres Therapeutics (NASDAQ:MCRB), Generate Biomedicines, Tessera Tx, Evelo Biosciences (EVLO), and Indigo Agriculture.

The role

We are looking for a Senior Scientist, Molecular Biology with experience inprotein engineering, complex DNA library design, and pooled screeningto help build next-generation DNA constructs for programmable medicines. This role is a good fit for someone who has worked on CAR/binder design and is comfortable designing and testing large libraries to support discovery and optimization of engineered proteins.

You will help build and scale platforms for plasmid DNA design, construction, and optimization, with a focus on practical, high-throughput workflows and data-driven decision making. We are looking for someone who brings strong technical skills, thinks critically about experimental design, and is comfortable working in a fast-paced, collaborative environment.

This role reports to the Director of Molecular Biology and includes management of one direct report. You will work closely with other scientists and group leads across the R&D team.

Key responsibilities

  • Using protein prediction models and ab initio modeling todevelop proteins of novel functionin silico and drive their selection and validation on wet bench
  • Deep expertisecharacterizing protein structure and functionincluding affinity, stability, etc.
  • Design and build complexDNA libraries, including barcoding strategies, to enable pooled screening and variant tracking.
  • Automation experience forarrayed screeningand other biochemical assays
  • Help build and scalehigh-throughput workflows for DNA and RNA production, screening, and data analysis.
  • Track record of demonstration execution of large-scale library screens to supportprotein engineering and CAR optimizationor binder identification and characterization
  • Protein production and characterization in both bacteria and mammalian cells
  • Contribute to plasmid and construct design for engineered proteins and cell-based systems.
  • Own construct QC, sequence analysis, and tracking of variants, including NGS-based workflows.
  • Work with external vendorsas needed, balancing internal builds and outsourcing to meet timelines.
  • Partner closely with other teams, including CMC, to provide designs, materials, and timelines.
  • Mentor junior scientistsand support strong practices in experimental design and data quality.
  • Maintain clear and reproducible records (ELN, sequence tracking, sample management).
  • Communicate results clearlyto cross-functional teams and leadership.

Who you are

We encourage all candidates with exemplary experience in related fields to apply.

Technical Expertise

Company Summary:

Serif Biomedicines, Inc. is a privately held, early-stage biotechnology company developing a novel approach to gene therapy that can address currently untreatable diseases.

Serif Biomedicines was founded by Flagship Pioneering, an innovation enterprise that conceives, creates, resources, and grows first-in-category life sciences companies.

Flagship Pioneering has created over 100 groundbreaking companies over the past twenty years, all of which are pioneering novel and proprietary biological, industrial, and engineering approaches to solve major needs in human health and sustainability. These companies include Moderna (MRNA), Syros Pharmaceuticals (SYRS), Seres Therapeutics (NASDAQ:MCRB), Generate Biomedicines, Tessera Tx, Evelo Biosciences (EVLO), and Indigo Agriculture.

The role

We are looking for a Senior Scientist, Molecular Biology with experience inprotein engineering, complex DNA library design, and pooled screeningto help build next-generation DNA constructs for programmable medicines. This role is a good fit for someone who has worked on CAR/binder design and is comfortable designing and testing large libraries to support discovery and optimization of engineered proteins.

You will help build and scale platforms for plasmid DNA design, construction, and optimization, with a focus on practical, high-throughput workflows and data-driven decision making. We are looking for someone who brings strong technical skills, thinks critically about experimental design, and is comfortable working in a fast-paced, collaborative environment.

This role reports to the Director of Molecular Biology and includes management of one direct report. You will work closely with other scientists and group leads across the R&D team.

Key responsibilities

  • Using protein prediction models and ab initio modeling todevelop proteins of novel functionin silico and drive their selection and validation on wet bench
  • Deep expertisecharacterizing protein structure and functionincluding affinity, stability, etc.
  • Design and build complexDNA libraries, including barcoding strategies, to enable pooled screening and variant tracking.
  • Automation experience forarrayed screeningand other biochemical assays
  • Help build and scalehigh-throughput workflows for DNA and RNA production, screening, and data analysis.
  • Track record of demonstration execution of large-scale library screens to supportprotein engineering and CAR optimizationor binder identification and characterization
  • Protein production and characterization in both bacteria and mammalian cells
  • Contribute to plasmid and construct design for engineered proteins and cell-based systems.
  • Own construct QC, sequence analysis, and tracking of variants, including NGS-based workflows.
  • Work with external vendorsas needed, balancing internal builds and outsourcing to meet timelines.
  • Partner closely with other teams, including CMC, to provide designs, materials, and timelines.
  • Mentor junior scientistsand support strong practices in experimental design and data quality.
  • Maintain clear and reproducible records (ELN, sequence tracking, sample management).
  • Communicate results clearlyto cross-functional teams and leadership.

Who you are

We encourage all candidates with exemplary experience in related fields to apply.

Technical Expertise

  • BS with 14+ years, MS with 12+ years, or PhD with 5+ years of relevant industry experience in molecular biology, bioengineering, or a related field.
  • Deep expertise inprotein engineering and CAR
  • Proven track record designing andbuilding complex DNA libraries, including barcoding strategies for pooled screening.
  • Strong command of molecular cloning and plasmid design in high-throughput settings.
  • Demonstrated ownership oflarge-scale library screens, from design through execution and data interpretation.
  • Expert-level experience withNGS-based library analysis, variant tracking, and sequence QC.
  • Ability to operate effectively in cross-functional teams and drive work forward in a fast-paced environment.
  • Experience mentoring or managing junior scientists.

Leadership & Collaboration

  • Proven ability tolead complex projectsand influence cross-functional teams.
  • Strong mentorship skills with commitment to developing others. Previous technical or professionalmanagement experience.
  • Excellent communication skills, with the ability to translate complex ideas across disciplines.

Values and Behaviors:

Flagship is an experiment in institutional, entrepreneurial, and innovation practiced in the context of a small company with an insurgent mindset. We are seeking individuals with an entrepreneurial spirit, strong communication skills, and comfort in working in and contributing to a dynamic and cross-functional team environment.

At Flagship, we recognize there is no perfect candidate. If you have some of the experience listed above but not all, we encourage you to apply anyway. Experience comes in many forms, skills are transferable, and passion goes a long way. We are dedicated to building diverse and inclusive teams and look forward to learning more about your unique background. The level of the role will be commensurate with the education and years of experience of the identified candidates.

Flagship Pioneering and our ecosystem companies arecommitted to equal employment opportunityregardless 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.

Privacy Notice for Applicants:When you apply for a role at Flagship Pioneering or one of its portfolio companies, we collect and use personal information you provide (such as your name, contact details, work history, and application materials) to evaluate your application, communicate with you, and comply with legal obligations. Your application data is processed through Greenhouse, our applicant tracking system, and may also be reviewed using AI-assisted screening tools. We do not sell your personal information. California residents have rights under the CCPA/CPRA including to know, delete, and opt out of the sharing of their personal information. If you are located in the EU or UK, we process your data under GDPR and you have rights to access, rectify, and erase your data. To exercise your rights or for questions, contact privacy@flagshippioneering.com.

The salary range for this role is $126,000 - $181,500. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. Serif Biomedicines currently offers healthcare coverage, annual incentive program, retirement benefits and a broad range of other benefits. Compensation and benefits information is based on Serif Biomedicines's good faith estimate as of the date of publication and may be modified in the future.

Privacy Notice for Applicants:When you apply for a role at Flagship Pioneering or one of its portfolio companies, we collect and use personal information you provide (such as your name, contact details, work history, and application materials) to evaluate your application, communicate with you, and comply with legal obligations. Your application data is processed through Greenhouse, our applicant tracking system, and may also be reviewed using AI-assisted screening tools. We do not sell your personal information. California residents have rights under the CCPA/CPRA including to know, delete, and opt out of the sharing of their personal information. If you are located in the EU or UK, we process your data under GDPR and you have rights to access, rectify, and erase your data. To exercise your rights or for questions, contact privacy@flagshippioneering.com.

Frequently Asked Questions

Where is the job located, and is it remote/hybrid/on-site?
The job is located in Cambridge, MA USA. The posting does not specify a remote or hybrid work-mode policy.
What are the required qualifications and experience levels for this role?
Candidates need a BS with 14+ years, an MS with 12+ years, or a PhD with 5+ years of relevant industry experience in molecular biology, bioengineering, or a related field. Deep expertise in protein engineering, CAR, and building complex DNA libraries is required.
What are the key responsibilities of the Senior Scientist?
Key responsibilities include developing proteins in silico using prediction models, characterizing protein structure and function, designing complex DNA libraries, executing large-scale library screens, scaling high-throughput DNA/RNA production workflows, and mentoring junior scientists.
What is the salary range for this position?
The salary range for this role is $126,000 - $181,500. Final compensation depends on the candidate's qualifications, skills, competencies, and experience.
What benefits does the company offer?
Serif Biomedicines currently offers healthcare coverage, an annual incentive program, retirement benefits, and a broad range of other benefits.
Who will I report to, and will I have any direct reports?
You will report directly to the Director of Molecular Biology. This role also includes the management of one direct report, as well as mentoring junior scientists.

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Job Information

Source: greenhouse
AI Relevance: 65/100 (Relevant)
Remote Type: onsite
Allowed Locations: Cambridge, MA USA
Skills & Tags:
Molecular Biology

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