Senior Software Engineer

Varsity Capital; Paris; Hybride; EUR 60 000 - 78 000; Plein temps

Avantages offerts par ce poste

Stock options

Conference sponsorships

International team

Meal vouchers

Mental health support

Training budget

Sabbatical leave

Office culture

Résumé du poste

C12 Quantum Electronics in Paris seeks a Senior Software Engineer to shape the future of quantum measurement. You will build the framework that runs experiments on quantum computers, collaborating with R&D and engineering teams to deliver scalable software.

The role emphasizes ownership of the software lifecycle, high-performance backend systems, and mentoring while aligning with a culture of curiosity and scientific rigor. Paris-based with a vibrant international team.

Qualifications

• 5+ years of experience building backend or data-intensive apps.
• Proficiency in Python as the primary language.
• Experience with message brokers and relational DBs (PostgreSQL, SQLAlchemy).
• Experience with orchestration tools like Prefect or Airflow is a plus.
• Background in physics, engineering, or a quantitative field preferred.
• Curious, adaptable, and eager to learn new languages/frameworks.
• Excellent English communication in collaborative environments.

Responsabilités

• Lead design and development of the core quantum measurement software framework with high performance and maintainability.
• Translate complex experimental requirements into robust software solutions with R&D teams.
• Define and document unified architecture for instrument control, data storage, and measurement orchestration.
• Champion strong software practices: code reviews, design discussions, CI/CD, automated testing.
• Own full software lifecycle: deliver robust, secure, scalable solutions for quantum R&D.
• Mentor junior engineers and model best practices in code quality and system design.

Connaissances

Backend systems

Python programming

Data-intensive apps

English communication

Formation

Physics/Engineering background

Outils

RabbitMQ

ZeroMQ

PostgreSQL

SQLAlchemy

Kafka

Prefect

Airflow

Description du poste

Founded in 2020 and based in the heart of Paris, C12’s mission is to be at the center of one of the biggest technological breakthroughs of the century and change the course of history by building a universal quantum computer.

At C12, we believe that achieving a true breakthrough in quantum computing requires rethinking the fundamentals. That’s why our founders—deeply rooted in academic and engineering excellence—have chosen carbon nanotubes as the building blocks of our quantum processors. This ultra-pure material dramatically reduces error rates, boosts performance, and minimizes hardware overhead—key ingredients for scalable, fault‑tolerant quantum computing. By crafting a unique approach that scales, we aim to revolutionize quantum computing just as silicon transformed classical computing.

Since our founding, we’ve raised over €25 million in funding, published 11 scientific papers, and secured 8 patents. Today, our fast‑growing team of 80+, including 25 PhDs, has over 26 nationalities represented. We have our own cutting‑edge lab spaces in Paris' historic Panthéon district, where scientists, engineers, and innovators work side‑by‑side to tackle some of the most exciting technical challenges of our time.

If you're passionate about shaping the future of quantum technology and want to make a real impact, C12 offers a unique environment to grow, learn, and innovate.

Your role at C12 Quantum Electronics:

The Software team is here to assist and facilitate the work of the research teams towards building a quantum computer.

As a Senior Software Engineer, you will be at the forefront of shaping the future of quantum measurement and help build the framework that runs experiments on quantum computers. Your expertise will drive the development and innovative solution that bridges the gaps between our R&D and engineering, enabling breakthrough in quantum technology.

Key responsibilities:

• Lead the design and development of our core quantum measurement software framework, ensuring high performance and long-term maintainability
• Partner with our R&D and other engineering teams at C12 to translate complex experimental requirements into robust, scalable software solutions
• Define and document the unified architecture for instrument control, high-throughput data storage, and measurement orchestration to support framework growth
• Champion rigorous software practices, including comprehensive code reviews, proactive design discussions, and robust CI/CD and automated testing pipelines
• Take ownership of the full software lifecycle, delivering robust, secure, and scalable solutions that meet the rigorous demands of quantum R&D
• Cultivate a culture of continuous learning by mentoring junior engineers and leading by example in code quality and system design

About you:

• 5+ years of experience building robust backend systems or data-intensive applications
• You are comfortable working with Python as a primary language; if coming from another background, you are eager to master the ecosystem
• You’re familiar or comfortable working with message brokers (e.g., RabbitMQ, ZeroMQ, Kafka) and relational databases (PostgreSQL), SQLAlchemy, etc
• Prior experience with orchestration tools like Prefect or Airflow is a strong plus
• A background in physics, engineering, or another quantitative field is a strong plus
• You are curious, adaptable, ready to discover new languages/frameworks/apis
• A problem solver that tries to use the best tool for the job
• You communicate clearly in English and work well in collaborative development environments

What we offer:

• 60,000 euros - 78,000 euros yearly base salary
• Stock options for every employee (BSPCE/ESOP)
• Sponsored trip to conferences around the world
• A highly dynamic international team
• Swile meal vouchers
• Mental health support with moka.care
• Training budget/ Annual Learning & Development Allowance
• Sabbatical leave (after 2 years in the company)
• Vibrant office culture (two office spaces in the heart of Paris, team lunches, offsite events, Friday breakfasts..)

You should join us if...

• You like hands-on work and technology
• You want to contribute to achieving landmark results in quantum computing, making a difference in the emerging quantum technologies
• You want to work within a team of 80+ people with various backgrounds in nanofabrication, quantum electronics, and carbon nanotube science to create a revolutionary quantum computing processor
• You want to thrive in an exceptional scientific environment with several industrial and academic partners
• You share our values (excellence, scientific integrity, diversity, curiosity, and care) and want to help us define our product-focused culture and ambition to accelerate

We still encourage even if you don’t meet all the requirements. Rest assured, we are committed to finding the right fit for our team and are open to adjusting compensations based on skills and experiences.

Applications from women are especially welcomed!