Full-Stack Software Engineer

What you'll do

Are you a passionate Full Stack Engineer looking to work in a dynamic and innovative environment? Are you eager to learn and grow in a collaborative and supportive setting? Join our high-performance Tools and Services team within the Scientific Information Service Group, where you will contribute to core open science platforms such as INSPIREHEP, SCOAP3, and CERN Analysis Preservation, along with machine-learning driven discovery and workflow systems that connect publications, data, and software across high energy physics. You will work on modern, high impact services used by thousands of researchers worldwide and collaborate closely with experts across CERN to deliver platforms that enable discovery, reproducibility, and Open Science.

Your responsibilities

Help developing INSPIRE AI, an advanced Retrieval-Augmented Generation (RAG) system that leverages the INSPIRE dataset to provide accurate, source-backed answers in high energy physics. You will help design high-quality scientific paper embeddings, build and optimise the backend with Python, LangChain, and FastAPI, contribute to the React frontend development, and work on robust evaluation methods and metrics to ensure reliability.
Engage in a variety of projects as part of an agile team, adapting to shifting requirements and milestones. Your flexibility and creativity will be key in addressing the team's evolving needs.
Contribute to the development and operation of various services, which are crucial for supporting thousands of users in the global research community annually.
Collaborate with the CERN IT department and other prestigious (external) institutions to design, develop, and deploy innovative tools and services.
Regularly enhance your skills and grow your expertise by contributing to open-source projects, addressing unique challenges, and seizing exciting opportunities that align with your engineering interests and strengths.

Still here? Let's make a quick check about

Your profile

You have professional experience in developing and operating production systems over several years.
You have experience with Python and LangChain, including designing retrieval-based AI systems.
You have experience integrating or developing AI-driven features in real applications.
You have experience building modern frontend applications with ReactJS.
You have experience working with relational databases, preferably PostgreSQL, and can write efficient and well-structured SQL queries.
You collaborate effectively within engineering teams using Git and platforms such as GitHub.
You have been exposed to MCP servers and multi-component service architectures.
Your studies focused on Computer Science.

Your skills

You have a strong understanding of software engineering principles and clean coding practices.
You can design and implement features across the full stack.
You understand embedding creation and RAG evaluation, and you have a creative and exploratory mindset for improving LLM-driven retrieval systems.
You have strong problem-solving skills and can work effectively within a team.
You have a good understanding of container orchestration concepts, with familiarity in Kubernetes seen as an advantage.
You are familiar with search technologies such as OpenSearch or Elasticsearch.
You understand continuous integration and deployment practices.
You understand cloud concepts and infrastructure as code.
Spoken and written English, with a commitment to learn French.

Ideal start date: 01/03/2026

Contract duration: 24 month contract

Job flexibility: Fully Onsite

Global Benefits at CERN

A monthly stipend between 6287-6911 Swiss Francs per month (tax free) depending on your degree.
30 days of paid leave per year plus 2 weeks annual closure.
Coverage by CERN’s comprehensive health insurance scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
Family, child and infant monthly allowances depending on your individual circumstances.
A relocation package (installation grant and travel expenses) depending on your individual circumstances.
Possibility to extend your contract up to 36 months.
On-the-job and formal training including language classes.

Let's get you ready

Be sure to meet the eligibility criteria

You are a national of a CERN Member State or Associate Member State.
By the application deadline, you have a master’s degree with 2 to 6 years of professional experience since graduation or a PhD with a maximum of 3 years of professional experience since graduation. You are not eligible with only a bachelor’s degree.
You have never had a CERN fellow or graduate contract before.
Please pay attention to the additional criteria and requirements for this specific position and mentioned above.

You will need these documents to complete your application

Your CV (English or French)
Any document you consider relevant to your application
A copy of your most relevant diploma or a certificate of achievement from your school (if you don't yet have your paper diploma)

Your CERNDepartment

The RCS sector oversees all research activities at CERN, including LHC and non-LHC programmes, and manages the scientific computing infrastructure and services essential for research and experiments.

Overview of CERN

Discover a world where the impossible is made possible!

At CERN, the European Organization for Nuclear Research, we are pushing the frontiers of science and technology. Our groundbreaking work brings together not only physicists but also a diverse range of professionals from engineering, technical, scientific, and administrative fields. Together, we foster an environment where innovation and collaboration thrive.

Every day, we face exciting new challenges and opportunities to contribute to cutting-edge research that shapes our understanding of the universe. We meet these challenges through the diverse perspectives within our teams, ensuring every contribution is valued and driving our shared sense of inclusion and purpose. Diversity is a core value of CERN since its foundation, and it remains central to our mission and continued success.

If you are ready to be part of a dynamic, inclusive community pushing the boundaries of knowledge, CERN is the place where your curiosity and skills can thrive. Be part of our mission to uncover what lies at the heart of the universe! TAKE PART!

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Still have a doubt ? Here are the most frequently asked questions

What should I expect during my first week at CERN?

Your onboarding at CERN includes a comprehensive induction programme, which starts with an official welcome session at the beginning of each month. In addition, you will receive important information both before and after your arrival to ensure a smooth transition into your new role. This process is designed to help you get acquainted with CERN’s environment, your team, and the tools and systems you’ll be using.
How big would the team be?

The size of the team you'll be working with at CERN depends on the specific role and department. Some teams are small and highly specialized, while others are larger and more interdisciplinary. During the interview process, you'll have the opportunity to learn more about the team structure for the position you are applying for.
What is the working language at CERN?

The working languages at CERN are English and French. However, it is not always mandatory to speak both languages to work at CERN. We offer language training to help you acquiring the other language.
What support does CERN provide for relocation?

CERN does not offer direct assistance with relocation. However, depending on your role and specific criteria, you may be eligible for certain benefits such as an installation allowance and coverage of travel expenses to join CERN. These benefits are designed to help ease the transition when relocating to the Geneva area. For more information, please consult the “Salary, Benefits and Support“ page.
Do I need a visa to work at CERN?

Whether you need a visa to work at CERN depends on your nationality and the duration of your stay. CERN assists with the necessary visa and work permit processes for its employees and visitors. The specific requirements will be communicated to you during the recruitment process.
What would my salary be?

Salaries at CERN are determined by a structured scale. Salaries are based on your role, qualifications, and experience, and are not subject to negotiation. Specific details will be provided as your application progresses. For more information, please refer to the dedicated page.