Software Engineer

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 60, including 20 PhDs, has over 20 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 :

Our core software team is looking for an additional senior software developer.

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

In close contact with the scientific teams, you will help build tools that help the scientific teams automate and improve their processes.

Alongside supporting the R&D teams, this role involves developing and maintaining the C12's emulator Callisto and its infrastructure, contributing to a range of projects with industrial collaborators while in close cooperation with our theory and quantum algorithm teams.

You are expected to be curious, adaptable and ready to discover new languages/frameworks/apis.

We want a problem solver that tries to use the best tool for the job.

About You:

• You have 5+ years of experience in software development
• Having experience with python is a plus, though not mandatory if you have experience in several other languages
• Experience with REST API is a plus
• Experience with Cloud based technologies (AWS) is a plus
• A background in physics (through studies or work) is a plus
• You have an interest in new technologies like quantum computing
• Good communication in English (verbal and written)
  
  
  

What we offer:

• Stock options for every employee (BSPCE/ESOP)
• Two incredible office spaces in the heart of Paris (both next to the famous Panthéon!)
• Sponsored trip to conferences around the world
• A highly dynamic international team
• Swile meal vouchers
• Vibrant office culture (team lunches, offsite events, Friday breakfasts..)
• Mental health support with moka.care
• Training budgets/ Annual Learning & Development Allowance
• Sabbatical leave (after 2 years in the company)
  
  
  

You should join us if...

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 60-people team 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.

C12 encourages all who feel qualified to apply. Recruitment decisions are based solely on qualifications, skills, knowledge and experience. Applications from women are particularly welcomed.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.