Senior Software Engineer

About the role

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: - You have 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