Backend Python Engineer

As a Backend Python Engineer at CERN, you will design, build and operate backend services that support scientific discovery and open access for the High Energy Physics community. You will work on data pipelines, REST APIs, search infrastructure, and AI-driven retrieval systems, contributing to open source projects used worldwide.

Responsibilities

• Drive the modernisation of the INSPIRE backend and expand the team's Model Context Protocol services.
• Align digitisation and archival services with the team's technology stack and deliver a large scale migration to the Access to Memory (AtoM) service.
• Review and migrate custom harvests to Apache Airflow, automating pipelines where appropriate.
• Evolve Apache Airflow ingestion and curation pipelines to improve data quality, deduplication, enrichment and source coverage.
• Expand Model Context Protocol services from pilot to a consistent, documented and maintainable interface for AI clients.
• Develop and optimise search and discovery functionality on OpenSearch including relevance tuning and indexing strategies.
• Deliver and oversee migration of archival items maintaining consistent metadata and data quality.
• Develop and automate connections between services to enable reliable content flow.
• Prepare ingestion pipelines for new file ingestion harmonised with other applications.
• Design, document and deliver REST APIs for internal and external use.
• Apply automated testing, code review, monitoring, CI/CD, and support production through containerised deployments and performance tuning.
• Contribute outputs back to the open source community to advance Open Science.

Requirements

• 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.
• Demonstrated experience building and operating backend services in Python in a production environment.
• Solid track record with web frameworks such as Django, Flask or FastAPI and with relational and document databases.
• Hands on experience designing REST APIs.
• Practical experience with search engines such as OpenSearch, including indexing and relevance tuning.
• Familiarity with containerised deployments, version control with Git and CI and CD workflows.
• Experience contributing to open source projects and working in a collaborative engineering team is highly valued.
• Your studies focused on Computer Science.

Skills

• Python Backend Development
• Django
• Flask
• FastAPI
• REST API Design
• Relational Databases
• Document Databases
• OpenSearch
• Search Engine Indexing
• Relevance tuning
• Containerized Deployments
• Git
• CI/CD Workflows
• Open-source Contribution
• Collaborative engineering

Languages

English, French