HR Business Partner

Our Mission Reflection is a research lab making intelligence open and accessible for everyone to use, customize, and build on. We build open models that let anyone control their intelligence and help shape the future of AI. Our mission: make intelligence open and accessible to all. About the Role The HR Business Partner will serve as a strategic advisor to functional leaders across technical and non-technical teams. This role is responsible for driving organizational effectiveness, supporting high-performance standards, and guiding leaders through complex people decisions. This foundational role will help build the HRBP function from the ground up: establishing core management toolkits, strengthening org design rigor, advising on performance and flight risk, and acting as connective tissue between leaders and the broader People team. You’ll help ensure we scale with intentionality, high performance, and sound judgment, while laying the groundwork for future org growth. What You’ll Do Strategic Leadership Partnership Partner with leaders to strengthen team performance and organizational health Advise on org design, role clarity, and team structure Support workforce planning aligned to business objectives Coach managers on feedback, accountability, and leadership effectiveness Guide leaders through change and scaling challenges Performance & Talent Management Coach managers through performance reviews, calibration, and promotion decisions Uphold high performance standards and consistency across teams Support talent planning and succession conversations Guide performance improvement and complex people decisions Ensure decisions are thoughtful, consistent, and well-documented Build scalable frameworks for separation and performance management practices Building for Scale Identify gaps in people practices and implement pragmatic, scalable solutions Partner cross-functionally to evolve people frameworks as the company grows What You Bring 7+ years of experience in an HR Business Partner role, ideally in high-growth or technology environments Strong experience with employee relations and workplace investigations Experience advising senior leaders and influencing decision-making Demonstrated ability to build HR frameworks in scaling organizations Deep knowledge of US employment practices; UK exposure is a plus Strong judgment, discretion, and ability to navigate ambiguity Ability to balance business needs with a fair and consistent employee experience What We Offer: We believe that to make intelligence open and accessible to all, you need to start at the foundation. Joining Reflection means building from the ground up as part of a talent-dense team. You will help define our future as a company, and help define the future of open foundational models. We want you to do the most impactful work of your career with the confidence that you and the people you care about most are supported. Top-tier compensation: Salary and equity structured to recognize and retain our talent globally. Stock options: Everyone who joins and contributes to Reflection's success gets to share in the upside through stock options. Health & wellness: Comprehensive medical, dental, vision, and life, with an annual wellness allowance. Meals: Lunch and dinner are provided in the office daily. Life & family: 22 weeks paid parental leave for all new birthing and non-birthing parents, including adoptive and surrogate journeys. Vacation days: Unlimited paid time off in the U.S. and 30 days in the U.K. Sponsorship support: We sponsor visas to help exceptional talent join our team and support long‑term immigration pathways where applicable. Team building: We have regular off‑sites, happy hours, and team celebrations. #J-18808-Ljbffr