Senior AI/ML Engineer (RAG & LLM Specialist)

Santex is a US-based global company founded in 1999, with 25 years of experience in the software industry. Headquartered in California with offices in Córdoba, Argentina, its talent network spans over 18 countries thanks to its flexible, remote-first culture. Santex specializes in custom enterprise software development, operating through Hubs that include eCommerce, BIM, Mobility, Content Delivery, Integration, Web & Mobile Development, Cloud Computing, Artificial Intelligence (AI), Data Science, IT Consulting, and Services. The company is committed to making a positive impact across three dimensions: economic, social, and environmental.

Job Description: 

We are seeking a Senior AI/ML Engineer specialized in Retrieval-Augmented Generation (RAG) and Large Language Models (LLMs) to join our team. The ideal candidate will have extensive experience in the entire lifecycle of LLM-based solutions, from prompt engineering and fine-tuning to designing and deploying RAG architectures for enterprise applications that require factual grounding and external data integration.

Responsibilities

• Design, develop, and deploy end-to-end solutions based on LLMs and RAG architecture.

• Develop and implement strategies for data retrieval, indexing, and vector database management to optimize RAG performance.

• Conduct prompt engineering and potentially fine-tuning (e.g., LoRA) of LLMs for specific business tasks.

• Collaborate with product and engineering teams to define and implement AI solutions focused on intelligent search, summarization, and conversational interfaces.

• Analyze, clean, and pre-process complex, unstructured datasets relevant to RAG systems.

• Evaluate and improve the quality, accuracy, and latency of deployed LLM and RAG solutions.

• Stay updated with the latest advancements in LLMs, RAG frameworks (e.g., LangChain, LlamaIndex), and AI industry trends.

Requirements

• Bachelor’s degree in Computer Science, Data Science, or a related quantitative field.

• 5+ years of experience in machine learning, AI development, or specialized NLP roles.

• Expert proficiency in Python and relevant ML/AI libraries (e.g., NumPy, Pandas, scikit-learn).

• Proven experience designing and implementing RAG systems in production environments.

• Deep understanding of Large Language Models (LLMs), their capabilities, limitations, and techniques like prompt engineering and grounding.

• Experience with vector databases (e.g., Pinecone, Chroma, Milvus) and embedding models.

• Experience deploying ML/AI solutions on cloud platforms (e.g., AWS, GCP, or Azure).

• Excellent verbal and written communication skills in Advanced English.

Desirable

• Experience with deep learning frameworks (TensorFlow or PyTorch).

• Experience in fine-tuning LLMs using methods like LoRA/QLoRA.

• Familiarity with frameworks for building LLM applications (e.g., LangChain, LlamaIndex).

• Experience with MLOps practices for LLM lifecycle management.

• Familiarity with Agile development methodologies.