Phasecraft is the quantum algorithms company. We are building the mathematical foundations for quantum computing applications that solve real-world problems. Founded in 2019 by Toby Cubitt, Ashley Montanaro, and John Morton, we are based in London and Bristol in the UK and opened an office in Washington DC in 2024, led by Steve Flammia. In 2025 we completed a $34m Series B funding round co-led by Plural, existing investor Playground Global, and Novo Holdings’ Quantum Fund in its first direct quantum software investment.

Phasecraft’s unprecedented access to today’s best quantum computers – through partnerships with Google, IBM, Quantinuum and QuEra – provides us with unique opportunities to develop foundational IP, inform the development of next-generation quantum hardware, and accelerate the commercialisation of high-value breakthroughs.

As we grow, we are committed to maintaining a collaborative, mission driven culture where our people feel supported, developed and inspired. To support this we are looking to hire a HR Business Partner to join our team as a trusted advisor to our founders, managers and staff, delivering outstanding people support while helping us scale effectively and sustainably. The HR Business Partner will balance strategic input such as organisation design, engagement, and development with hands-on execution in areas such as employee relations, performance, onboarding and compliance.

Job Description

• Partner with leaders and managers to provide expert HR advice and coaching.
• Partner with leadership to embed company values and foster an inclusive, high-performance culture.
• Lead on organisational design and talent reviews as the company scales.
• Build trusted relationships across all levels, ensuring employees have a consistent and positive experience.
• Design and deliver performance review cycles, goal-setting frameworks, and feedback tools.
• Maintain and update company policies and the employee handbook; ensure compliance with employment law across multiple jurisdictions.
• Support managers with capability, coaching, and development conversations.
• Manage employment documentation, contracts, and visa support with external providers as needed.
• Work closely with payroll and external providers to ensure accurate and timely people administration.
• Oversee onboarding and induction processes, ensuring consistency across global offices.
• Manage probation processes and support managers in providing structured feedback.
• Own employee data accuracy and HR systems (HRIS).

Requirements

Essential Criteria

• 5+ years’ HR experience, including time as a business partner or HR generalist in a deep-tech, R&D, or engineering-led start-up or scale-up.
• Proven ability to operate independently with excellent judgment and pragmatism in ambiguous, complex environments.
• Experience building scalable people processes in a growing company.
• Strong working knowledge of UK employment law and exposure to international employment contexts (US ideal).
• Proven ability to manage employee-relations issues with professionalism and discretion.
• Excellent communication and interpersonal skills and a track record of being a trusted, credible, empathetic, and commercially minded HR professional.

Desirable Criteria

• Experience implementing or optimising HR systems (HRIS, performance tools, ATS) and building scalable workflows.
• CIPD qualification or equivalent HR certification.

The closing date for applications is 4 October 2026.