Interim HR Manager

Flagship Pioneering is a biotechnology company that invents and builds platform companies that change the world. We bring together the greatest scientific minds with entrepreneurial company builders and assemble capital to allow them to take courageous leaps. Those big leaps in human health and sustainability exponentially accelerate scientific progress in areas ranging from cancer detection and treatment to nature-positive agriculture.

What sets Flagship apart is our ability to advance biotechnology by uniting life science innovation, company creation, and capital investment under one roof in a way that is largely without precedent. Our scientific founders, entrepreneurial leaders, and professional capital managers are each aligned around an institutionalized process that enables us to innovate and transform for the benefit of people and planet.

Many of the companies Flagship has founded have addressed humanity’s most urgent challenges: vaccinating billions of people against COVID-19, curing intractable diseases, improving human health, preempting illness, and feeding the world by improving the resiliency and sustainability of agriculture.

Flagship has been recognized twice on FORTUNE’s “Change the World” list, an annual ranking of companies that have made a positive social and environmental impact through activities that are part of their core business strategies and has been twice named to Fast Company’s annual list of the World’s Most Innovative Companies.

ABOUT THE ROLE

Flagship Pioneering is seeking an Interim HR Manager to provide full-cycle HR support across a portfolio of multiple early-stage life sciences companies during a planned leave of absence. This is a high-autonomy, high-breadth role — you'll be the primary HR resource for companies ranging from 1 to 15 employees, each at a different stage of building out their people infrastructure.

This role is ideal for an experienced HR manager who thrives in ambiguity, can context-switch rapidly across organizations, and knows how to prioritize in environments where everything feels urgent.

Duration: ~5 months | Location: On-Site 4 days per week, Cambridge, MA | Reports To: Senior HR Business Partner

WHAT YOU'LL DO

Employee Lifecycle & Operations

• Deliver day-to-day HR services including onboarding, performance management, employee relations, and offboarding across all portfolio companies

• Maintain HR records and ensure data integrity across HRIS and other people systems

• Assist with compensation benchmarking, job leveling, and offer structuring as new roles are created

Cross-Functional Collaboration

• Align closely with Talent Acquisition, Payroll, Legal, and Learning & Development to maintain consistency across portfolio companies

• Ensure all companies remain compliant with applicable federal, state, and local employment laws; partner with outside counsel as needed

Administrative Support

• Provide general HR administrative support to the Senior HR Business Partner as needed, including scheduling, document management, tracking action items, and coordinating across portfolio companies

WHAT WE'RE LOOKING FOR

• 5+ years of HR generalist and/or business partner experience, ideally supporting multiple business units or startup-stage companies simultaneously

• Strong working knowledge of multi-state employment law and HR compliance requirements

• Prior experience in biotech, life sciences, pharmaceuticals, or fast-growing startup environments

• Experience supporting companies in early stages of HR infrastructure build-out (no handbook, no formal processes — you've been there before)

• Comfortable operating independently with minimal direction; able to manage competing priorities across organizations

• Strong command of confidential matters, data-driven decision-making, and interpersonal communication

• SHRM-CP/SCP or PHR/SPHR preferred

WHY THIS ROLE

You'll have real impact across a diverse set of companies during a critical period of growth. No two days look the same, and you'll have the autonomy to make decisions and drive outcomes.

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 $40 - $100. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. Flagship Pioneering currently offers healthcare coverage, annual incentive program, retirement benefits and a broad range of other benefits. Compensation and benefits information is based on Flagship Pioneering'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.