Junior Software Engineer

Ersilia is a non-profit organization building open source AI/ML tools to support infectious disease research across the Global South. Founded in 2020, the Ersilia team has developed an array of methods and infrastructure to provide free service to researchers working in resource-limited settings, mostly in Sub-Saharan Africa. Ersilia’s current focus is to speed up drug discovery for global health threats like malaria, tuberculosis, antimicrobial drug resistance or schistosomiasis.

We are looking for a Junior Software Engineer who is enthusiastic about open-source development and wants to grow at the intersection of software engineering, artificial intelligence, and global health. The ideal candidate is curious, collaborative, and eager to learn within a small, mission-driven technical team.

The successful candidate will work under the direct supervision of Marina Miñarro (Lead Software Engineer, PhD) and will spend a significant portion of their time on the Ersilia Model Hub — our flagship open-source platform and a recognised Digital Public Good. The Hub allows biomedical researchers worldwide to run AI/ML models for drug discovery without complex setup, and is used by laboratories across Sub-Saharan Africa and other low-resourced settings.

1. Contribute to the Ersilia Model Hub (open-source platform for AI-driven drug discovery):

— Implement new features and fix bugs under the guidance of the Lead Software Engineer.

— Help integrate, maintain, and update machine learning models into the Hub, including testing their correctness and ensuring compatibility with the platform.

— Write clean, well-documented, and tested Python code.

— Track issues and progress on GitHub Projects.

— Follow and help improve coding standards and best practices.

1. Collaborate with cross-functional teams, including data scientists, biomedical researchers, and external partners:

— Attend weekly team meetings and contribute to technical discussions.

— Help maintain and improve end-user documentation.

1. Support the open-source community:

— Help prepare GitHub issues for external contributors.

— Participate in mission-aligned training programmes when relevant.

— Bachelor’s degree (or final year) in Computer Science, Software Engineering, Bioinformatics, or a related field.

— Proficiency in Python: writing scripts, functions, and working with libraries.

— Basic understanding of machine learning concepts — enough to integrate and maintain models within an existing platform.

— Familiarity with Git and collaborative development workflows (pull requests, code review).

— Clear communicator, team-oriented, curious and eager to learn.

— Good written and spoken English (working language of the team).

— Based in Barcelona or able to relocate by August 2026. Optional hybrid: 3 days on-site, 2 days remote.

— Master’s degree in Computer Science or related fields

— Own personal or academic software projects on GitHub or similar platforms.

— Experience with Linux / command-line environments.

— Basic knowledge of Docker or containerisation.

— Exposure to software testing (unit tests, CI pipelines).

— Hands-on experience with Python machine learning packages (e.g. scikit-learn, PyTorch, TensorFlow).

— Familiarity with agentic AI tools and frameworks (e.g. Claude by Anthropic).

— Familiarity with open-source community practices

Previous experience or demonstrable interest in bioinformatics, life sciences or drug discovery will be highly considered.

— Structured onboarding and close mentorship by the Lead Software Engineer.

— Career development plan with a clear path towards a mid-level role.

— Collaborative and mission-driven work environment.

— Opportunities to contribute to open-source projects with global impact.

— Funding for relevant training, certifications, and conference participation.

— Flexible working hours.

— Great office space at Norrsken House, Barcelona.

Only candidates already legally able to work in Spain will be considered.