Senior ML/LLM Engineer (API & Fullstack)

Sopra Steria seeks a senior-level machine learning and LLM engineer combining data science expertise with robust API development and full-stack engineering practices. The role emphasizes end-to-end lifecycle management of ML solutions from conception through production deployment.

Position: Senior ML/LLM Engineer (API & Fullstack) - English Mandatory
Location: Carrer de Casanova, Barcelona, Spain
Type: Full-time, permanent contract

Key Responsibilities:

• Develop and validate statistical and machine learning models in Python
• Engineer classification, regression, and predictive models using industry-standard libraries
• Implement NLP solutions extracting insights from unstructured text
• Build LLM-based systems using GPT-4, Claude 3, Llama 3, and Gemini
• Design RAG systems with vector database integration
• Construct orchestrated LLM workflows using appropriate frameworks
• Create scalable production APIs and integrate solutions into applications

Required Skills & Tech Stack:

Data Science: NumPy, Pandas, Polars, SciPy, Scikit-learn, XGBoost, LightGBM, CatBoost, TensorFlow/Keras, PyTorch
NLP & LLMs: NLTK, spaCy, Hugging Face Transformers, Sentence Transformers, LangChain, LlamaIndex, Haystack
Vector Databases: Pinecone, Weaviate, ChromaDB, FAISS
Competencies: Prompt engineering, fine-tuning (LoRA/QLoRA), RAG architecture design

Benefits:

• 23 days annual leave
• Continuous professional development and certifications
• Life/accident insurance
• Flexible benefits (healthcare, meal vouchers, childcare assistance, mobility)
• Comprehensive onboarding and career development planning

English mandatory.