Human Resources Business Partner

Human Resources Business Partner Torrance, California, United States Apply for Position Or refer someone Job Openings Human Resources Business Partner About the job Human Resources Business Partner Why Castelion, Why Now Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts. This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact. Human Resources Business Partner (HRBP) The Human Resources Business Partner (HRBP) serves as a strategic advisor to leaders and employees, helping drive organizational effectiveness, talent development, and workforce performance across Castelion. This role partners closely with business leaders to align people strategies with company objectives, providing guidance on organizational design, performance management, employee relations, leadership development, and workforce planning. The ideal candidate thrives in a fast-paced, high-growth environment and is passionate about building scalable people practices that enable exceptional talent to perform at their highest level while supporting Castelion's mission and continued growth. Responsibilities Strategic Business Partnership Partner with business leaders to improve organizational performance, workforce planning, and team effectiveness, maintaining a 95%+ leadership satisfaction rating through proactive HR support. Provide strategic coaching that enables leaders to resolve 90%+ of employee relations and performance matters without escalation. Develop and execute people strategies that improve retention, organizational health, and business outcomes, contributing to year-over-year improvements in key talent metrics. Organizational Effectiveness & Talent Strategy Lead workforce planning, talent reviews, and organizational design initiatives that ensure 100% of critical roles have succession or staffing plans. Partner with leaders to identify and develop high-potential talent, achieving 90%+ completion of annual talent calibration and development plans. Performance Management & Employee Relations Coach leaders through performance management, investigations, and employee relations matters while maintaining 100% legal and policy compliance. Ensure 95%+ of performance improvement plans, corrective actions, and investigations are completed within established timelines and documentation standards. Leadership Coaching & Development Coach managers to improve leadership capability, accountability, communication, and decision-making, resulting in measurable improvements in team performance. Partner with leaders to increase manager effectiveness, with 90%+ of leaders demonstrating improvement against leadership development objectives. Culture & Operational Excellence Identify and implement process improvements that reduce administrative effort and improve service delivery, targeting 20%+ annual efficiency gains across HR processes. Drive People initiatives that reinforce Castelion's culture of ownership, accountability, urgency, and continuous improvement while maintaining 95%+ completion of key annual People programs. Basic Qualifications 5+ years of progressive HR experience, including HR Business Partner experience supporting technical, engineering, manufacturing, and/or operations organizations. Demonstrated experience supporting both exempt and non-exempt employee populations in a fast-paced environment. Experience supporting workforce planning, talent development, organizational design, and performance management initiatives. Strong understanding of employment law, employee relations, and HR best practices. Demonstrated ability to influence without...