Application & Algorithm Support Engineer - Quantum Computing (HPC Context)

Quandela is a French deeptech company building Europe's first general-purpose photonic quantum computers. Our systems are already available through the cloud and are now also deployed on-site for strategic academic and industrial partners.

Beyond hardware, Quandela develops the full software stack, including Perceval, our open-source simulation library, Merlin, our platform to program and run quantum algorithms, as well as the cloud and on-site infrastructure required to operate these systems in real research environments.

In 2024, as part of the EuroQCS-France consortium (GENCI & CEA), Quandela provided the European research community with early remote access to a 6-qubit photonic quantum computer. This initiative will scale in 2025 with the on-site deployment of Lucy, our 12-qubit system, installed at CEA's Très Grand Centre de Calcul (TGCC) and directly coupled to the Joliot-Curie supercomputer. This deployment marks a major milestone, combining HPC and quantum computing within a single hybrid infrastructure.

With the deployment of on-site photonic quantum hardware, researchers are moving from theoretical exploration to real execution. They now run quantum algorithms under concrete technical constraints, inside HPC environments, and often under strong scientific and institutional expectations.

This creates new needs. Researchers expect reliable, high-level support that goes beyond classic ticket handling. They need a technical point of contact who understands both algorithmic intent and operational realities, and who can help translate ideas into workflows that actually run.

To address this, Quandela is building a dedicated Application Support & User Enablement cell. This role focuses on the algorithm and application layer of the stack and works in close coordination with a QPU-focused counterpart to cover the full system.

You will be the main point of contact for GENCI and CEA researchers on quantum algorithms and applications. Your responsibility is not only to ensure that the system works technically, but that it is usable, understandable and productive for its users. The role is strategic and highly visible, both internally and within the French and European quantum ecosystems. Over time, you will become a reference person for researchers using Quandela's platform, while actively contributing to structuring usage and building a sustainable user community around the machine.

On-site presence:

More than 3 days per week on-site at CEA's Très Grand Centre de Calcul (TGCC) in Bruyères-le-Châtel, home of the Joliot-Curie supercomputer. Being close to the machine, the users and the HPC teams is essential to the impact of this role.
The remaining time can be hybrid from Massy / Paris-Saclay.

Requirements

Support & debugging

You will handle application-level support requests related to execution issues, compilation problems, scripting errors or performance limitations. You will debug algorithm workflows and environment configurations, validate installations and updates, and work directly with users to understand the root causes of issues.

In many cases, the problem is not a bug but a mismatch between user expectations and platform constraints. This can involve perfectible workflows, algorithms that are theoretically valid but operationally unrealistic, or habits inherited from other quantum frameworks or QPU types. A key part of your role is to identify these situations early and help users adjust their approach.

User enablement

User enablement is a core dimension of this role. It involves spending time with researchers, on-site at TGCC or remotely, to understand their scientific objectives, level of familiarity with the platform and practical constraints.

Based on these interactions, you will translate system constraints into clear and actionable guidance for users, while bringing structured feedback to Quandela's internal teams. When issues recur, your role is not to fix them endlessly, but to capitalize on them.

This includes producing clear documentation, onboarding guides, execution checklists, reference workflows and practical best practices that prevent common errors. These materials serve external users, internal teams and future support engineers, and aim to progressively raise the overall level of autonomy across the user base.

Community & adoption

As usage grows, you will contribute to structuring and animating the user community around the system. This can include 1:1 sessions to unblock specific use cases, small practical workshops, thematic sessions or shared feedback moments between users.

Over time, this role can naturally extend beyond the local TGCC environment to include other laboratories, cloud users and the broader quantum ecosystem, always with the same application- and user-focused posture.

Coordination & collaboration

You will take part in regular technical reviews with HS and HLST teams and work closely with Quandela's algorithm, software, product and sales teams. Your position allows you to feed real-world usage insights directly into product improvements and roadmap discussions.

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During the first months, you will onboard on the support workflows, progressively take ownership of tickets, contribute to initial documentation and start running user sessions. After several months, you are expected to be recognized as a trusted point of contact by users, able to identify recurring pain points and propose structured improvements.

Within the first year, the role is expected to evolve from mostly reactive support to proactive user enablement, including community animation, workshops and the definition of best practices and KPIs for the support function.

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We are looking for candidates with a strong support mindset and real experience working close to end users in technical environments. The ideal profile has three to five years of experience in application or user support and is comfortable operating at the interface between complex software systems and demanding users.

Strong Python skills are essential, as Python is at the core of Merlin, Perceval and most user scripts. Familiarity with at least one quantum framework is expected, together with solid debugging practices and the ability to understand and troubleshoot algorithmic workflows.

Beyond technical skills, this role requires a strong capacity for documentation and user enablement. The ability to explain technical constraints clearly and patiently to researchers, translate complex concepts into actionable guidance, and structure knowledge in a reusable way is critical to success in this position.

Professional English is required, and conversational French is needed for daily interactions with CEA and Quandela teams.

Experience with HPC environments, applied mathematics or QML is a plus, as is prior exposure to research infrastructures or deeptech contexts. We particularly value profiles who enjoy knowledge sharing, community interaction and contributing to long-term adoption rather than one-off support.

Benefits

What We Offer: Salary: €45–60k depending on scope: 

• 45k: strong support experience, ready to grow. 
• 50–55k: autonomous, can handle complex issues. 
• 60k+: senior, able to contribute to community and product feedback. 

Profit-sharing & company savings plan. 
100% health coverage (Alan), Swile meal vouchers, transport/mobility support. 

A Final Word on 'Support'
At Quandela, support is not a back-office function. It is where science meets reality. 
As a Support Engineer, you are the bridge between pioneering researchers and a working quantum machine. The algorithms you help run will shape both today's experiments and tomorrow's roadmap. 

It's strategic, it's vital and it's the kind of support that defines whether Europe succeeds in quantum computing adoption. 
So ... If you're ready to turn quantum promise into real impact for researchers across Europe, let's talk