Junior AI Scientist

Workster

Lisboa

Hybrid

EUR 45,000 - 65,000

Full time

14 days+

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Benefits offered by this job

Competitive salary plus equity potential

Subsidised apartment if relocating

Health insurance

Company-funded travel to global AI conferences

Personal learning budget

Company-funded travel

Job summary

A cutting-edge AI startup in Lisbon is seeking an Artificial Intelligence Researcher to assist with research and development. The role involves working on autonomous AI models, collaborating closely in a dynamic environment. Ideal candidates should have strong foundations in programming and mathematics, alongside a proactive learning mindset. The position offers a hybrid work model, competitive salary, health benefits, and relocation support.

Qualifications

Strong fundamentals in linear algebra, probability, calculus, or optimisation.
Experience with Python, Jupyter, and Git.
Familiarity with PyTorch or TensorFlow.
Understanding of evaluation metrics such as accuracy, F1, or perplexity.
Vector databases (e.g., FAISS or Qdrant).
Understanding of evaluation metrics such as accuracy, F1, or perplexity.
Familiarity with Docker and basic cloud concepts is a plus.
A proactive, learning-driven mindset.
No formal degree required—skills, passion, and initiative matter

Responsibilities

Assist in research, prototyping, and feature development.
Run and fine-tune Large Language Models (LLMs).
Design and run tests to improve accuracy, safety, and reliability.
Preparing and cleaning datasets for training and evaluation.
Designing and running tests to improve accuracy, safety, and reliability.
Write clear, maintainable Python code for experiments and prototypes.
Collaborate closely with senior scientists to learn best practices in AI optimisation, scaling, and evaluation.
Track experiments and analyse results using tools like Weights & Biases or MLflow.

Skills

Python

Jupyter

Git

PyTorch

TensorFlow

Hugging Face

Vector DBs

FAISS

Qdrant

Evaluation metrics

Docker

Cloud basics

Learning mindset

Tools

Weights & Biases

MLflow

Job description

Overview

Workster is partnering with a cutting-edge AI startup on a mission to give models the ability to act autonomously—running code, fixing systems, and analysing data—so humans can focus on strategy and creativity. Their work goes beyond traditional language models, focusing on AI that can perform real, meaningful tasks. If you’re excited by the idea of applying advanced AI research to create practical, high-impact solutions, this is a great opportunity to join a small, fast-moving team where your contributions will be seen and valued.

Responsibilities

Assist in research, prototyping, and feature development to advance their Agentic LAM from proof-of-concept to production.
Running and fine-tuning Large Language Models (LLMs).
Implementing Retrieval-Augmented Generation (RAG) pipelines.
Preparing and cleaning datasets for training and evaluation.
Designing and running tests to improve accuracy, safety, and reliability.
Write clear, maintainable Python code for experiments and prototypes.
Collaborate closely with senior scientists to learn best practices in AI optimisation, scaling, and evaluation.
Track experiments and analyse results using tools like Weights & Biases or MLflow.

Qualifications

You don’t need to know everything on the list — but you should bring depth in at least one or two areas and the curiosity to learn more. For example:
Strong fundamentals in linear algebra, probability, calculus, or optimisation.
Python, Jupyter, Git.
PyTorch or TensorFlow.
Hugging Face Transformers for simple fine-tuning.
Vector databases (e.g., FAISS or Qdrant).
Understanding of evaluation metrics such as accuracy, F1, or perplexity.
Familiarity with Docker and basic cloud concepts is a plus.
A proactive, learning-driven mindset.
No formal degree required—skills, passion, and initiative matter

The Offer

Hybrid work in Lisbon with the option for multi-week remote blocks.
Competitive salary plus equity potential.
Subsidised apartment if relocating.
Health insurance, modern hardware, and a personal learning budget.
Company-funded travel to global AI conferences and events.
Work directly with experienced AI engineers and researchers, with strong mentorship opportunities.
Fast-paced startup environment with real ownership from day one.

Seniority level