Senior Scientist, Small Molecule Chemical Engineering

Job Description The Chemical Commercialization Technology (CCT) department, part of our Manufacturing Division, is seeking a highly motivated and collaborative scientist to join our team. This position offers the opportunity to provide technical leadership across a varied portfolio of late-stage small molecule development programs while working in a highly integrated environment with research, manufacturing, quality, regulatory and external partners. The Senior Scientist will apply chemical engineering and process development expertise to support the commercialization of late-stage and commercial small molecule drug substance processes. This role provides significant technical leadership and offers opportunities to influence process design, control strategies, technology transfers, validation programs, regulatory submissions, and lifecycle process improvements. The successful candidate will work across laboratory, pilot plant, and manufacturing environments to develop scientific understanding, assess process risks, and implement robust manufacturing solutions. The individual will collaborate with internal stakeholders and external partners to drive successful commercialization and continuous improvement initiatives. The candidate must demonstrate a strong commitment to safety, quality, and compliance, including adherence to current Good Manufacturing Practices (cGMPs), Good Documentation Practices (GDPs), data integrity principles, and participation in risk assessments, deviation investigations, change control activities and continuous improvement initiatives. Key Responsibilities Lead process understanding, characterization, and commercialization activities for small molecule drug substance manufacturing processes. Design and execute scientifically sound experimental programs using Quality Risk Management (QRM) and Quality by Design (QbD) principles. Apply statistical methods, Design of Experiments (DoE), and data-driven decision making to establish process robustness and control strategies. Develop, defend, and communicate technical recommendations to cross-functional teams, manufacturing sites, and senior leadership. Support technology transfer activities from development laboratories to pilot plants and commercial manufacturing facilities. Author and review technical reports, validation documents, regulatory filing content, control strategies, and lifecycle management documentation. Provide technical leadership during process performance qualification (PPQ), process validation, and commercial manufacturing campaigns. Lead or support investigations, risk assessments, change controls, deviations, and corrective and preventive actions (CAPAs). Collaborate with internal and external manufacturing partners to resolve technical challenges and implement process improvements. Utilize first-principles engineering, process modeling, and scale-up methodologies to support manufacturing and process optimization. Champion a culture of safety, compliance, operational excellence, and continuous improvement. Position Qualifications Education Ph.D. in Chemical Engineering or a related scientific discipline. OR B.S. or M.S. in Chemical Engineering or a related scientific discipline with a minimum of 5 years of relevant industrial experience. Required Experience and Skills Demonstrated experience in chemical process development, commercialization, or manufacturing support of small molecule pharmaceutical processes. Experience designing and executing experimental programs to solve complex chemical engineering and manufacturing challenges. Effective communication skills with the ability to present technical information to multiple audiences. Ability to work independently while collaborating effectively in multidisciplinary teams. Strong organizational, project management, and technical writing skills. Demonstrated commitment to safety, quality, and compliance. Preferred Experience and Skills Experience authoring or reviewing regulatory submissions (e.g., NDA, MAA, post-approval changes). Experience leading technology transfers between development, pilot plant, and commercial manufacturing environments. Hands-on expertise with unit operations commonly used in small molecule drug substance manufacturing, including; Chemical reactions, Work-up operations, Distillation, Crystallization, Filtration, Drying. Knowledge of statistical software and advanced data analysis tools (e.g., JMP, Minitab, Python). Experience applying Design of Experiments (DoE), Process Capability Analysis, and Multivariate Data Analysis. Familiarity with process analytical technologies (PAT), digital manufacturing tools, and advanced process monitoring approaches. Experience leading internal / external technical discussions. Knowledge of current Good Manufacturing Practices (cGMP), validation requirements, and pharmaceutical quality systems. Experience with mathematical modeling, process simulation, scale-up principles, and engineering calculations. Familiarity with ICH guidelines, Quality by Design (QbD), Quality Risk Management (QRM), and lifecycle process verification concepts. Required Skills: API Manufacturing, Chemical Engineering, Chemical Manufacturing, Commercialization, Design of Experiments (DOE), Manufacturing Processes, Manufacturing Technologies, Pharmaceutical Process Development, Process Control, Process Improvements, Process Scale Up, Product Commercialization, Small Molecule Synthesis, Technology Development, 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 $117,000.00 - $184,200.00 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: 1st - Day Valid Driving License: No Hazardous Material(s): n/a Job Posting End Date: 09/10/2026 *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.