Merck Posted August 11, 2026

Principal Scientist, Upstream Process Development

Rahway, New Jersey, United States of America FULL_TIME
Manufacturing & CMC Principal

Merck is the source of truth for this posting and owns the application process. We surface normalized context and market comparison you won't find on the original listing.

About this opportunity

Job Description

The Biologics Process Research & Development organization within our Research & Development Division is responsible for developing the drug substance manufacturing processes for our Company's biologics pipeline. We work closely with colleagues in Discovery, Pre-clinical and Early Development to rapidly develop manufacturing processes for diverse biotherapeutics, and efficiently manufacture material to supply clinical trials. We are also responsible for late-stage process development and process characterization to prepare for commercial manufacturing.  We work with our partners in our Company Manufacturing Division to commercialize and launch new products.

We are seeking a highly motivated and experienced individual to join our team as a Principal Scientist. In this role, the successful candidate will lead cross-functional teams to develop CMC packages for our pipeline assets.  The successful candidate will also collaborate with fellow Bioprocess Development colleagues to develop and refine technical strategy related to next generation processing for assets in early- and late-stage clinical development. Applicants must have effective organizational and multi-tasking skills, demonstrated excellent scientific leadership, and superior written and oral communications abilities. A track record of leveraging data science and digital tools for delivering impactful solutions to complex problems are distinguishing. Evidence of strong cross-functional collaboration, experience successfully mentoring junior scientist, leading projects, and strong external presence through scientific excellence are expected.

JOB RESPONSIBILITIES:

The successful candidate will contribute to CMC development of our Company's pipeline, playing an active role in development of cell culture processes and transfer to clinical and commercial manufacturing sites. They will also develop strategies for process and pipeline-facing innovation. Responsibilities include:

Leading biologic upstream process development for first-in-human and commercial processes by efficiently developing high yield, robust and scalable cell culture processes.

Providing technical direction for process development, characterization, commercialization, and regulatory filing activities to ensure a smooth and clear path to successful PPQs an BLAs for our company pipeline.

Advancing upstream platform process technical strategy and championing creative process improvement initiatives

Initiating new collaborations to assess new technologies and industry strategies with relevance to our Company.

Collaborating with academia, industry partners, and vendors to drive development, innovation and adoption of new process technologies with broad impact to projects or platform.

Keeping current with the external patent and literature environment; actively presents and publishes externally and pursues patenting strategies.

Mentoring and educating junior scientists

Minimum education required:

Ph.D. with 6+ years of industry experience or Master with 8+ years industry experience in Chemical Engineering, Bioengineering, Biochemistry or a related field

Required experience and skills :

Proven record of accomplishments in upstream process and technology development with a strong scientific publication and presentation track record.

Experience in CHO fed-batch cell culture and a working understanding of downstream & analytics.

Understanding and hands-on experience on cell culture bioreactors including microbioreactors, bench-scale and pilot-scale bioreactors, and scaleup/tech transfer activities.

Working knowledge of cell culture media, CHO cell biology and metabolism, DOE statistics and computational fluid dynamics.

Ability to direct the planning, execution, analysis, and documentation of all stages of cell culture process development.

Ability to work in a matrixed team environment and collaborate with both internal and external partners including vendors.

Knowledge of biologics CMC development cycle.

Experience with late-stage commercial process development, technology transfer, scale-down model qualification and process characterization.

Demonstrated ability for taking initiative, creativity, and innovation in problem solving.

Demonstrated ability to develop staff to maximize utilization of talent and actively guides career development; builds strong and collaborative teams.

Preferred experience and skills:

Experience with state-of-the-art cell culture processes including intensified inoculum and perfusion process development.

Experience with high throughput microbioreactor systems, and advanced in situ analytics for process monitoring and control.

Expertise in media development, media/solution chemistry.

Background in data science approaches related to cell culture and predictive modeling e.g., metabolic flux analysis (MFA), omics, machine learning; experience integrating PAT efforts) and computational fluid dynamics (CFD).

Experience leading cross functional, program development teams.

Required Skills:

Adaptability, Cell Culture Process Development, Cell Line Development, Combination Products, Data Analysis, Finite Element Analysis (FEA), Innovative Thinking, Leadership Mentoring, Pharmaceutical Process Development, Professional Collaboration, Professional Networking, Quality by Design, Regulatory Filings, Strategic Thinking, Technology Transfer

Preferred Skills:

Current Employees apply HERE

Current Contingent Workers apply HERE

US and Puerto Rico Residents Only:

Our company is committed to inclusion, ensuring that candidates can engage in a hiring process that exhibits their true capabilities. Please click here if you need an accommodation during the application or hiring process.

As an Equal Employment Opportunity Employer, we provide equal opportunities to all employees and applicants for employment and prohibit discrimination on the basis of race, color, age, religion, sex, sexual orientation, gender identity, national origin, protected veteran status, disability status, or other applicable legally protected characteristics.  As a federal contractor, we comply with all affirmative action requirements for protected veterans and individuals with disabilities.  For more information about personal rights under the U.S. Equal Opportunity Employment laws, visit:

EEOC Know Your Rights

EEOC GINA Supplement​

We are proud to be a company that embraces the value of bringing together, talented, and committed people with diverse experiences, perspectives, skills and backgrounds. The fastest way to breakthrough innovation is when people with diverse ideas, broad experiences, backgrounds, and skills come together in an inclusive environment. We encourage our colleagues to respectfully challenge one another’s thinking and approach problems collectively.

Learn more about your rights, including under California, Colorado and other US State Acts

The salary range for this role is

$173,200.00 - $272,600.00

This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. An employee’s position within the salary range will be based on several factors including, but not limited to relevant education, qualifications, certifications, experience, skills, geographic location, government requirements, and business or organizational needs.

The successful candidate will be eligible for annual bonus and long-term incentive, if applicable.

We offer a comprehensive package of benefits.  Available benefits include medical, dental, vision healthcare and other insurance benefits (for employee and family), retirement benefits, including 401(k), paid holidays, vacation, and compassionate and sick days. More information about benefits is available at https://jobs.merck.com/us/en/compensation-and-benefits .

You can apply for this role through https://jobs.merck.com/us/en (or via the Workday Jobs Hub if you are a current employee). The application deadline for this position is stated on this posting.

San Francisco Residents Only:  We will consider qualified applicants with arrest and conviction records for employment in compliance with the San Francisco Fair Chance Ordinance

Los Angeles Residents Only:  We will consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with the requirements of applicable state and local laws, including the City of Los Angeles’ Fair Chance Initiative for Hiring Ordinance

Search Firm Representatives Please Read Carefully 

Merck & Co., Inc., Rahway, NJ, USA, also known as Merck Sharp & Dohme LLC, Rahway, NJ, USA, does not accept unsolicited assistance from search firms for employment opportunities. All CVs / resumes submitted by search firms to any employee at our company without a valid written search agreement in place for this position will be deemed the sole property of our company.  No fee will be paid in the event a candidate is hired by our company as a result of an agency referral where no pre-existing agreement is in place. Where agency agreements are in place, introductions are position specific. Please, no phone calls or emails.

Employee Status:

Regular

Relocation:

Domestic

VISA Sponsorship:

Yes

Travel Requirements:

10%

Flexible Work Arrangements:

Not Applicable

Shift:

Not Indicated

Valid Driving License:

No

Hazardous Material(s):

n/a

Job Posting End Date:

10/1/2026 *A job posting is effective until 11:59:59PM on the day BEFORE  the listed job posting end date. Please ensure you apply to a job posting no later than the day BEFORE the job posting end date.

Requisition ID:R399271

Job details

Seniority
Principal
Function
Manufacturing & CMC
Therapeutic area
Not listed
Location
Rahway, New Jersey, United States of America
Employment type
FULL_TIME

How this role compares

Computed from every other active Manufacturing & CMC role in our database, not just this employer's listings.

We currently track 393 comparable Principal Manufacturing & CMC roles across 56 biopharma companies.

393Comparable roles tracked
368Currently active
56Companies hiring similar roles
19Countries represented

Salary context

188 of 393 peers report a salary range (USD, annualized)

Peers share this role's job function and a matching or adjacent seniority level -- not necessarily the same therapeutic area or country.

This roleSubject $173,200/yr – $272,600/yr
Lowest disclosed · Senior Scientist II – CMC Developmental Sciences · AbbVie $0/hr – $0/hr (≈ $0–$0/yr)
Highest disclosed · Director, Global Automation Engineering · AbbVie $182,000/yr – $346,000/yr
Peer group range $0 – $264,000 (median $150,600)

Where these roles are based

Top locations among the 393 comparable roles

United States282
India42
Singapore10
Ireland9
Netherlands7
Switzerland6

+ 13 more countries

Seniority mix

393 of 393 peers have a known seniority level

Senior251
Principal78
Director64

Therapeutic area mix

2 of 393 peers have a known therapeutic area; the rest are genuinely unlabeled, not hidden

Oncology1
Vaccines & Infectious Disease1

Similar opportunities

The closest matches from our peer group, ranked by how similar they are, not how well you'd qualify for them -- treat this as market context, not a guaranteed shortlist; a weak match is labeled as one below.

60%similar
Lilly Indianapolis, Indiana, United States of America Principal
Same function Same seniority Same country
60%similar
Lilly Louisville, Colorado, United States of America Principal
Same function Same seniority Same country
60%similar
Lilly Indianapolis, Indiana, United States of America Principal
Same function Same seniority Same country
60%similar
Lilly Watertown, Massachusetts, United States of America Principal
Same function Same seniority Same country
60%similar
Lilly Indianapolis, Indiana, United States of America Principal
Same function Same seniority Same country
60%similar
Lilly Indianapolis, Indiana, United States of America Principal
Same function Same seniority Same country

How we calculate "similar"

No black box, no LLM guesswork: a deterministic score built from four normalized attributes. Here's this role's own peer group at different match levels, so you can see the mechanism, not just the result.

Every comparison starts from the same 100-point budget: 25 for working in the same function, 40 for the same therapeutic area, 20 for the same or adjacent seniority, 15 for the same country. A dimension we can't confirm on both sides contributes nothing, never a guess, never a free pass.

60%
Senior/Principal Scientist, Bioprocess Purification Development
Lilly · Indianapolis, Indiana, United States of America · Principal
Function Therapeutic area Seniority Country
60%
Senior Principal Scientist, Analytical Sciences
Lilly · Watertown, Massachusetts, United States of America · Principal
Function Therapeutic area Seniority Country
60%
Sr. Principal or Engineering Advisor - Agentic Lab Automation Integration
Lilly · Indianapolis, Indiana, United States of America · Principal
Function Therapeutic area Seniority Country
60%
Principal Scientist, Downstream Process Development
Merck · Rahway, New Jersey, United States of America · Principal
Function Therapeutic area Seniority Country
Unmatched or unknown dimensions score exactly the same: 0 points, never a partial guess. A role we know almost nothing about beyond its function bottoms out at 25%; it never inflates to 100% just because there's little to compare against. Seniority uses a defined ladder (Associate → Manager → Associate Director → Senior → Principal → Director → Senior Director → Executive/VP) so "Director" and "Senior Director" count as adjacent, but "Director" and "Executive/VP" do not.