Quantum Software

Software / Theory · Full-time · Hybrid · Paris, France

Preferred start date: Early January 2027

About Qluster

Qluster is a startup developing continuous-variable photonic quantum computers. By prioritizing architecture-first scalability, our ambition is to turn fundamental research into practical technology for healthcare, chemistry, sustainability and various applications.

We bring together physicists and engineers who value curiosity, initiative, and teamwork. Progress comes from open discussion, constructive challenges, and shared ownership of complex problems. Joining Qluster means helping shape both our core technology and the way we work.

Your role and responsibilities

Lead the development of Qluster’s internal software for continuous-variable measurement-based quantum computing (CV-MBQC). You will connect quantum circuit descriptions, photonic models and experimental constraints, with an initial focus on a validated simulation and circuit-mapping stack.

• Define the software architecture and development priorities with the systems architect and experimental scientists; provide technical guidance and review scientific code.
• Develop mappings from supported circuits to resource states, passive optical transformations, measurement sequences and outcome-dependent feed-forward, making encoding assumptions explicit.
• Implement and validate the gates, state preparations and measurement models required by the selected architecture, including relevant loss and noise processes.
• Choose numerical representations suited to Gaussian and non-Gaussian problems; quantify approximation errors, computational cost and the limits of each simulation.
• Build representative circuit benchmarks, automated tests, documentation and reproducible workflows; compare results with analytical references and experimental data.
• Maintain clear interfaces between simulation, compilation and hardware models, and evolve the stack as architectural choices and research priorities develop.

Basic qualifications and experience

• Master’s degree or PhD in physics, computer science, applied mathematics or a related field, or equivalent relevant experience.
• Strong Python and numerical computing skills, with experience developing scientific software used by other researchers or engineers.
• Solid understanding of quantum circuits and quantum measurement, with research or development experience in quantum simulation.
• Experience with version control, automated testing, code review and maintainable software design.
• Demonstrated ability to guide technical decisions, break open-ended problems into deliverable work and communicate modelling limitations.
• Collaborative working style, constructive feedback, and clear written and spoken scientific communication in English.

Preferred qualifications and experience

• Experience with CV quantum optics, cluster states, MBQC or bosonic encodings such as GKP codes.
• Experience with quantum compilation, adaptive measurements or interfaces between quantum algorithms and physical implementations.
• Familiarity with Fock-space methods, phase-space methods, tensor networks or stochastic simulation.
• Performance optimisation using compiled languages, GPUs or parallel computing; experience mentoring scientific software contributors.

What we offer

• Compensation: Salary package tailored to your experience and profile.
• Workplace flexibility: Hybrid work organization based in Paris.
• Benefits: Health insurance (50% employer-funded) and 50% public transportation reimbursement.
• Growth potential: As an early-stage startup, our employee benefits and workplace perks will expand and evolve alongside the growth and maturity of the company.

We are committed to an inclusive and accessible recruitment process and workplace. Should you need any accommodations at any stage, please let us know.