Quantum Software Engineer - Algorithms & Applications in Harwell

ABOUT THE COMPANY

Infleqtion is a global quantum technology company solving the world’s most challenging problems. The company harnesses quantum mechanics to build and integrate quantum computers, sensors, and networks. From fundamental physics to leading edge commercial products, Infleqtion enables “quantum everywhere” through our ecosystem of devices and platforms. Our mission is to commercialise atom-based quantum products that provide orders of magnitude improvements in performance and computing applications.

LOCATION

Infleqtion has offices in the USA, United Kingdom and Australia. This is a full‑time position in our Kidlington and Harwell offices. Our flexible working policy enables all full‑time employees to work up to 2 days a week from home as work permits.

POSITION SUMMARY

Infleqtion is seeking a Quantum Software Engineer to develop cutting‑edge applications and algorithms for next‑generation quantum computers. In this role, you will design, implement, and optimise quantum algorithms across domains such as simulation, optimisation, sensing‑enhanced workflows, and hybrid quantum‑classical computation. You will work closely with hardware, control, and research teams to translate theoretical advances into performant, executable workloads, leveraging modern quantum SDKs, compiler toolchains, and resource estimation frameworks. The ideal candidate combines strong foundations in quantum algorithms and computational mathematics with practical software engineering expertise, enabling them to build scalable, testable, and high‑impact quantum applications that push the boundaries of near‑term and fault‑tolerant quantum systems.

JOB RESPONSIBILITIES

• Conduct R&D toward cutting‑edge advances in quantum technology with a focus on quantum applications and algorithms.
• Deploy software optimisations to our cloud platform Superstaq using industry‑grade software engineering procedures including documentation, linting, testing, and type‑checking.
• Interface with customers of Superstaq to understand their needs and support them in a timely fashion.
• Contribute to development of government and commercial proposals and execution on global programmes.
• Collaborate with experimental physicists and software engineers to bridge the gap between theoretical concepts and practical implementation.
• Engage with the broader scientific community by publishing research findings in scientific journals and presenting at conferences.
• Stay up to date with the latest developments in quantum computer architecture, quantum compilation and related fields.
• Provide guidance and support to other team members, fostering a collaborative research environment.

QUALIFICATIONS

• Master’s degree in quantum applications, mathematics, engineering, physics or a directly related field.
• High proficiency in programming, with fluency in Python preferable.
• Experience with open‑source quantum software frameworks such as Cirq or Qiskit.
• Demonstrated ability to work and communicate with all levels of an organisation.
• Professional‑level communication skills, including verbal, written, and presentation skills.
• Demonstrated ability to work comfortably in a highly collaborative, cross‑functional, team‑oriented, and matrixed environment.
• Desire and demonstrated ability to thrive and produce results in a fluid, dynamic, and fast‑paced environment.
• Demonstrated ability to learn new and complex topics quickly.
• Resourceful problem‑solver who collaboratively identifies effective paths forward with demonstrated expertise in executing productisation efforts.
• Passion for solving complex problems and challenges in a highly technical and scientific environment.

Desirable Skills or Knowledge

• PhD in quantum computation, physics, computer science, or a directly related field.
• Familiarity with concepts in quantum computing such as error correction / fault tolerance, native gate decomposition, qubit mapping and routing, and variational quantum algorithms.
• Experience with material science applications of quantum computers.
• Familiarity with best practices of professional software engineering such as coverage, integration tests, type checking, unit tests, and version control.
• Experience with backend development with tools such as FastAPI for web frameworks and PostgreSQL/SQLAlchemy for databases.
• Experience with cloud development, especially on GCP and AWS.
• Familiarity with CI/CD, automated actions, issue tracking, version control, and other features on GitHub.
• Familiarity with security core best‑practices such as access control, encryption at rest, key rotation, and logging.
• Exposure to or interest in front‑end / GUI development, e.g., HTML/CSS, React, PyQt.

EQUAL OPPORTUNITY

Regardless of your interest in the quantum industry, you can take pride in the fact that Infleqtion is building an ecosystem of quantum technologies and commercial products, driving the industry towards the future. Studies reveal that while men apply for jobs when they meet an average of 60% of the requirements, women and other groups tend to apply only when they meet all the criteria. If you believe you have the potential but don't meet every single point in our job advertisement, please don’t hesitate to contact us! We would love to chat with you and see how you could bring great value to our team. Our goal is to find exceptional individuals who can enrich our team culture, actively contribute, and have a genuine passion for their work. Here you have freedom to embrace your whole self: who you love, your gender identity and expression, skin colour, age, appearance, disability, neurodiversity, DNA, military/veteran status, citizenship, and other factors that make up who you are. Your uniqueness is valued, welcomed, and appreciated here. We are dedicated to providing a positive workplace and base all employment decisions on your qualifications, performance, merits, as well as business needs. We are proud to be an Equal Employment Opportunity Employer.

COMPENSATION & BENEFITS

In addition to your base compensation, we offer a generous Total Rewards programme which includes:

• Competitive salary.
• Incentive Stock Option Plan.
• Generous company 10% pension contribution regardless of employee contribution.
• Unlimited PTO.
• BUPA healthcare after probation period.
• Cycle to work and Technology scheme.