Executive Assistant

Phasecraft; Greater London; On-site; GBP 30,000 - 50,000; Full time

Job summary

A quantum algorithms company in Greater London is seeking an experienced Executive Assistant to support a Co-Founder in their London office. The role involves managing a complex diary, coordinating travel, and ensuring smooth communication with stakeholders. Ideal candidates will have a strong background in supporting C-level executives in fast-paced environments, excellent time-management skills, and the ability to handle confidential information with discretion. Applications close on 11th January 2026.

Qualifications

• Proven experience supporting C-level executives in a fast-paced environment.
• Exceptional organisational and time-management skills.
• Ability to multitask and stay calm under pressure.

Responsibilities

• Manage the Co-Founder's complex diary and prioritise meetings.
• Triage and prioritise academic administrative tasks.
• Serve as point of contact for stakeholders.

Skills

Organisational skills

Time management

Problem-solving

Discretion and confidentiality

Communication skills

Job description

Phasecraft is a 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 commercialisation of high-value breakthroughs.

We are now looking to hire an Executive Assistant to support a Co-Founder in our London office and in his job as a Professor at a leading academic institution. This role requires an experienced individual with outstanding communication skills, the ability to anticipate needs before they arise and highly developed judgment skills.

Job Description

• Manage the Co-Founder’s complex and rapidly changing diary; prioritise meetings and commitments based on strategic importance to Phasecraft and in his academic appointment.
• Triage and prioritise complex and constantly changing academic administrative tasks and inbound requests, and assist in executing these.
• Manage inbox flow, prioritising communications and ensuring clarity.
• Track action items and deadlines, ensuring timely follow-through.
• Arrange complex domestic and international travel around scientific conferences, industry events and partner visits.
• Serve as point of contact for the Co-Founder and internal/external stakeholders, including investors, board members, customers, partners and students.
• Develop and refine systems that will optimise the Co-Founder’s productivity and ability to focus on technical priorities; protecting time for deep work, technical thinking and writing.
• Assist co-founder with life admin tasks where these free up time for higher-priority work tasks.
• Handle sensitive company and personal information with absolute confidentiality.
• Build strong relationships across the company to help the Co-Founder stay connected to priorities and progress.
• Collating and managing expense reports and reimbursements.

Essential criteria

• Proven experience supporting C-level executives, founders or senior leadership in a fast-paced environment.
• Exceptional organisational and time-management skills, with an ability to multitask, prioritise and stay calm under pressure.
• Demonstrated ability to act with discretion, confidentiality and professional judgement.
• Ability to proactively anticipate needs and solve problems.
• Strong initiative and comfortable working with minimal direction.
• Strong written and verbal communication skills with excellent attention to detail.

Desirable criteria

• Prior experience in a deep-tech, technology, research or scientific environment.

The closing date for applications is 11th January 2026.