Senior Human Resources Business Partner

Salary Range: $ To $ Annually

The Senior HR Business Partner
(Sr. HRBP) serves as a strategic and hands-on partner to leaders across Nucleus Radio Pharma, helping to build the people infrastructure needed to scale a fast-growing, GMP-regulated radiopharmaceutical organization. This role owns full-spectrum HR partnership – talent, employee relations, performance, organizational design, HR operations, and policy – ensuring HR practices are consistent, compliant, and aligned to Nucleus's operating rhythm.

This is a builder role as much as a partner role: the Sr. HRBP will help stand up scalable HR processes and frameworks appropriate for a ~55-person startup operating in an IND/FDA-regulated, GMP environment, while maintaining the flexibility and responsiveness leaders expect at this stage of growth.

• Serve as the primary day-to-day HR partner for assigned leaders and employees, providing practical guidance on employee relations, performance management, attendance, workplace concerns, team dynamics, and policy application.
• Meet regularly with leaders to review staffing needs, employee performance, open positions, retention risks, organizational changes, and emerging people issues. Track agreed-upon actions through completion.
• Translate business and operational priorities into specific HR actions, including hiring plans, onboarding, training, performance expectations, development plans, succession planning, and employee communications.
• Support organizational changes by drafting job descriptions, teaching, coaching and clarifying responsibilities, evaluating reporting relationships, updating organizational charts, and coordinating employee communications and implementation steps.
• Partner with leaders to identify workforce gaps, develop staffing plans, and ensure the organization has the appropriate roles, capabilities, and coverage to support operational and regulatory requirements.
• Coach managers on setting clear expectations, providing timely feedback, documenting performance concerns, developing corrective action plans, and addressing issues consistently and promptly.
• Monitor employee trends, including turnover, engagement, absenteeism, performance concerns, and staffing levels, and recommend specific actions based on the data.
• Coordinate closely with Talent Acquisition, Payroll, Benefits, Legal, and HR Operations to ensure employee matters and organizational changes are implemented accurately and on time.

• Manage, coach on employee relations matters with sound judgment, consistency, and appropriate documentation, escalating and coordinating with leadership as needed.
• Ensure HR policies, practices, and documentation meet the standards required in a GMP and FDA-regulated environment.
• Maintain compliant, audit-ready HR documentation and recordkeeping practices.

• Support onboarding and workforce planning efforts in partnership with hiring managers as Nucleus scales.
• Facilitate performance management processes, including goal-setting, feedback cycles, and performance improvement support.
• Partner with leaders on succession planning, career pathing, and talent development for key roles.
• Own full-cycle recruiting for assigned functions – intake, job posting, sourcing, screening, interviewing, and offer negotiation – in partnership with hiring managers.
• Build and maintain a scalable recruiting process and candidate pipeline appropriate for a fast-growing, GMP-regulated organization.
• Partner with hiring managers to define role requirements, build structured interview plans, and calibrate candidate evaluation criteria.
• Ensure recruiting practices, interview documentation, and offer processes…