Backend Python Engineer (OSI-SIS-TS-2026-128-GRAP)

As a Backend Python Engineer, you will join the Tools and Services section within the Scientific Information Service, the team that powers scientific discovery and open access across the High Energy Physics community.

Our systems include INSPIRE, SCOAP3, CERN Analysis Preservation and a tool facilitating access to CERN’s institutional memory.

You will design, build and operate services that ingest, curate, search and expose millions of scientific records to a worldwide audience.

You will work on high‑throughput data pipelines, REST APIs, search infrastructure and the integration of AI‑driven retrieval into production systems.

Responsibilities

• Modernise the INSPIRE backend, expand Model Context Protocol services, and lead the migration of digitisation and archival services to the Access to Memory (Ato M) service.
• Review and migrate custom harvests to Apache Airflow, retain those that are necessary, and redesign or retire others.
• Work with curators to decide what to keep, automate pipelines where appropriate, and keep a human in the loop for expert decisions.
• Improve ingestion and curation pipelines for scientific metadata and full‑text at scale, enhancing data quality, deduplication, enrichment and source coverage.
• Expand Model Context Protocol services across INSPIRE and other team services for external AI clients.
• Develop and optimise search and discovery functionality on Open Search, including relevance tuning and indexing strategies.
• Align digitisation and archival services onto shared frameworks and deployment tooling.
• Deliver the migration of 35 000 archival items to Ato M, maintaining metadata quality.
• Automate connections between services, enabling reliable content flow.
• Design, document and deliver REST APIs for internal, partner and third‑party use.
• Apply automated testing, code review, monitoring, CI/CD and support production through containerised deployments and performance tuning.
• Contribute the team’s outputs back to the open‑source community to advance Open Science.
• Profile
• Experience building and operating backend services in Python in a production environment; strong track record with Django, Flask or Fast API.
• Hands‑on experience designing REST APIs.
• Practical experience with search engines such as Open Search, including indexing and relevance tuning.
• Familiarity with containerised deployments, Git version control and CI/CD workflows.
• Experience contributing to open‑source projects and collaborating in engineering teams is highly valued.

Skills

• Proficiency in Python and modern backend practices.
• Solid understanding of REST API design, async programming and testing.
• Experience with Postgre SQL and search technologies such as Open Search.
• Knowledge of Docker, Kubernetes and CI/CD pipelines.
• Understanding of metadata standards and large‑scale data processing.
• Clear, well‑documented, maintainable code.
• Strong problem‑solving skills and attention to detail.
• Ability to work in a multicultural team and ownership‑driven mindset.
• Proficient in English; commitment to learn French is a plus.
• Eligibility Criteria
• National of a CERN Member or Associate Member State.

• Professional background in Computer Science (or related field) with

• Master’s degree and 2–6 years post‑graduation experience;
• or Ph D and up to 3 years post‑graduation experience.
• No prior CERN fellow or graduate contract.
• Additional Information

Job closing date

Contract duration: 24 months, with a possible extension up to 36 months.

Working hours: 40 hours per week.

Job flexibility: Hybrid.

Target start date: 01-November-2026.

Field of work: Software Engineering and IT.

Benefits

• Monthly stipend between 6 3772–7 04 Swiss francs (tax free) depending on degree.
• 30 days paid leave per year plus 2 weeks annual closure.
• Coverage by CERN’s comprehensive health‑insurance scheme for yourself, spouse and children.
• Membership of the CERN Pension Fund.
• Family, child and infant monthly allowances according to circumstances.
• Relocation package (installation grant and travel expenses) on a case‑by‑case basis.
• Possibility to extend contract up to 36 months.
• On‑the‑job and formal training, including language classes.
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